Stringpublic final class String extends Object implements Comparable, CharSequence, SerializableThe String class represents character strings. All
string literals in Java programs, such as "abc", are
implemented as instances of this class.
Strings are constant; their values cannot be changed after they
are created. String buffers support mutable strings.
Because String objects are immutable they can be shared. For example:
String str = "abc";
is equivalent to:
char data[] = {'a', 'b', 'c'};
String str = new String(data);
Here are some more examples of how strings can be used:
System.out.println("abc");
String cde = "cde";
System.out.println("abc" + cde);
String c = "abc".substring(2,3);
String d = cde.substring(1, 2);
The class String includes methods for examining
individual characters of the sequence, for comparing strings, for
searching strings, for extracting substrings, and for creating a
copy of a string with all characters translated to uppercase or to
lowercase. Case mapping is based on the Unicode Standard version
specified by the {@link java.lang.Character Character} class.
The Java language provides special support for the string
concatenation operator ( + ), and for conversion of
other objects to strings. String concatenation is implemented
through the StringBuilder(or StringBuffer)
class and its append method.
String conversions are implemented through the method
toString, defined by Object and
inherited by all classes in Java. For additional information on
string concatenation and conversion, see Gosling, Joy, and Steele,
The Java Language Specification.
Unless otherwise noted, passing a null argument to a constructor
or method in this class will cause a {@link NullPointerException} to be
thrown.
A String represents a string in the UTF-16 format
in which supplementary characters are represented by surrogate
pairs (see the section Unicode
Character Representations in the Character class for
more information).
Index values refer to char code units, so a supplementary
character uses two positions in a String.
The String class provides methods for dealing with
Unicode code points (i.e., characters), in addition to those for
dealing with Unicode code units (i.e., char values). |
| Fields Summary |
|---|
| private final char[] | valueThe value is used for character storage. | | private final int | offsetThe offset is the first index of the storage that is used. | | private final int | countThe count is the number of characters in the String. | | private int | hashCache the hash code for the string | | private static final long | serialVersionUIDuse serialVersionUID from JDK 1.0.2 for interoperability | | private static final ObjectStreamField[] | serialPersistentFieldsClass String is special cased within the Serialization Stream Protocol.
A String instance is written initially into an ObjectOutputStream in the
following format:
TC_STRING (utf String)
The String is written by method DataOutput.writeUTF.
A new handle is generated to refer to all future references to the
string instance within the stream. | | public static final Comparator | CASE_INSENSITIVE_ORDERA Comparator that orders String objects as by
compareToIgnoreCase. This comparator is serializable.
Note that this Comparator does not take locale into account,
and will result in an unsatisfactory ordering for certain locales.
The java.text package provides Collators to allow
locale-sensitive ordering. |
| Constructors Summary |
|---|
public String()Initializes a newly created {@code String} object so that it represents
an empty character sequence. Note that use of this constructor is
unnecessary since Strings are immutable.
this.offset = 0;
this.count = 0;
this.value = new char[0];
| public String(byte[] bytes, int offset, int length, Charset charset)Constructs a new {@code String} by decoding the specified subarray of
bytes using the specified {@linkplain java.nio.charset.Charset charset}.
The length of the new {@code String} is a function of the charset, and
hence may not be equal to the length of the subarray.
This method always replaces malformed-input and unmappable-character
sequences with this charset's default replacement string. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
if (charset == null)
throw new NullPointerException("charset");
checkBounds(bytes, offset, length);
char[] v = StringCoding.decode(charset, bytes, offset, length);
this.offset = 0;
this.count = v.length;
this.value = v;
| public String(byte[] bytes, String charsetName)Constructs a new {@code String} by decoding the specified array of bytes
using the specified {@linkplain java.nio.charset.Charset charset}. The
length of the new {@code String} is a function of the charset, and hence
may not be equal to the length of the byte array.
The behavior of this constructor when the given bytes are not valid
in the given charset is unspecified. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
this(bytes, 0, bytes.length, charsetName);
| public String(byte[] bytes, Charset charset)Constructs a new {@code String} by decoding the specified array of
bytes using the specified {@linkplain java.nio.charset.Charset charset}.
The length of the new {@code String} is a function of the charset, and
hence may not be equal to the length of the byte array.
This method always replaces malformed-input and unmappable-character
sequences with this charset's default replacement string. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
this(bytes, 0, bytes.length, charset);
| public String(byte[] bytes, int offset, int length)Constructs a new {@code String} by decoding the specified subarray of
bytes using the platform's default charset. The length of the new
{@code String} is a function of the charset, and hence may not be equal
to the length of the subarray.
The behavior of this constructor when the given bytes are not valid
in the default charset is unspecified. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
checkBounds(bytes, offset, length);
char[] v = StringCoding.decode(bytes, offset, length);
this.offset = 0;
this.count = v.length;
this.value = v;
| public String(byte[] bytes)Constructs a new {@code String} by decoding the specified array of bytes
using the platform's default charset. The length of the new {@code
String} is a function of the charset, and hence may not be equal to the
length of the byte array.
The behavior of this constructor when the given bytes are not valid
in the default charset is unspecified. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
this(bytes, 0, bytes.length);
| public String(StringBuffer buffer)Allocates a new string that contains the sequence of characters
currently contained in the string buffer argument. The contents of the
string buffer are copied; subsequent modification of the string buffer
does not affect the newly created string.
String result = buffer.toString();
this.value = result.value;
this.count = result.count;
this.offset = result.offset;
| public String(StringBuilder builder)Allocates a new string that contains the sequence of characters
currently contained in the string builder argument. The contents of the
string builder are copied; subsequent modification of the string builder
does not affect the newly created string.
This constructor is provided to ease migration to {@code
StringBuilder}. Obtaining a string from a string builder via the {@code
toString} method is likely to run faster and is generally preferred.
String result = builder.toString();
this.value = result.value;
this.count = result.count;
this.offset = result.offset;
| String(int offset, int count, char[] value)
this.value = value;
this.offset = offset;
this.count = count;
| public String(String original)Initializes a newly created {@code String} object so that it represents
the same sequence of characters as the argument; in other words, the
newly created string is a copy of the argument string. Unless an
explicit copy of {@code original} is needed, use of this constructor is
unnecessary since Strings are immutable.
int size = original.count;
char[] originalValue = original.value;
char[] v;
if (originalValue.length > size) {
// The array representing the String is bigger than the new
// String itself. Perhaps this constructor is being called
// in order to trim the baggage, so make a copy of the array.
int off = original.offset;
v = Arrays.copyOfRange(originalValue, off, off+size);
} else {
// The array representing the String is the same
// size as the String, so no point in making a copy.
v = originalValue;
}
this.offset = 0;
this.count = size;
this.value = v;
| public String(char[] value)Allocates a new {@code String} so that it represents the sequence of
characters currently contained in the character array argument. The
contents of the character array are copied; subsequent modification of
the character array does not affect the newly created string.
int size = value.length;
this.offset = 0;
this.count = size;
this.value = Arrays.copyOf(value, size);
| public String(char[] value, int offset, int count)Allocates a new {@code String} that contains characters from a subarray
of the character array argument. The {@code offset} argument is the
index of the first character of the subarray and the {@code count}
argument specifies the length of the subarray. The contents of the
subarray are copied; subsequent modification of the character array does
not affect the newly created string.
if (offset < 0) {
throw new StringIndexOutOfBoundsException(offset);
}
if (count < 0) {
throw new StringIndexOutOfBoundsException(count);
}
// Note: offset or count might be near -1>>>1.
if (offset > value.length - count) {
throw new StringIndexOutOfBoundsException(offset + count);
}
this.offset = 0;
this.count = count;
this.value = Arrays.copyOfRange(value, offset, offset+count);
| public String(int[] codePoints, int offset, int count)Allocates a new {@code String} that contains characters from a subarray
of the Unicode code point array argument. The {@code offset} argument
is the index of the first code point of the subarray and the
{@code count} argument specifies the length of the subarray. The
contents of the subarray are converted to {@code char}s; subsequent
modification of the {@code int} array does not affect the newly created
string.
if (offset < 0) {
throw new StringIndexOutOfBoundsException(offset);
}
if (count < 0) {
throw new StringIndexOutOfBoundsException(count);
}
// Note: offset or count might be near -1>>>1.
if (offset > codePoints.length - count) {
throw new StringIndexOutOfBoundsException(offset + count);
}
int expansion = 0;
int margin = 1;
char[] v = new char[count + margin];
int x = offset;
int j = 0;
for (int i = 0; i < count; i++) {
int c = codePoints[x++];
if (c < 0) {
throw new IllegalArgumentException();
}
if (margin <= 0 && (j+1) >= v.length) {
if (expansion == 0) {
expansion = (((-margin + 1) * count) << 10) / i;
expansion >>= 10;
if (expansion <= 0) {
expansion = 1;
}
} else {
expansion *= 2;
}
int newLen = Math.min(v.length+expansion, count*2);
margin = (newLen - v.length) - (count - i);
v = Arrays.copyOf(v, newLen);
}
if (c < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
v[j++] = (char) c;
} else if (c <= Character.MAX_CODE_POINT) {
Character.toSurrogates(c, v, j);
j += 2;
margin--;
} else {
throw new IllegalArgumentException();
}
}
this.offset = 0;
this.value = v;
this.count = j;
| public String(byte[] ascii, int hibyte, int offset, int count)Allocates a new {@code String} constructed from a subarray of an array
of 8-bit integer values.
The {@code offset} argument is the index of the first byte of the
subarray, and the {@code count} argument specifies the length of the
subarray.
Each {@code byte} in the subarray is converted to a {@code char} as
specified in the method above.
checkBounds(ascii, offset, count);
char value[] = new char[count];
if (hibyte == 0) {
for (int i = count ; i-- > 0 ;) {
value[i] = (char) (ascii[i + offset] & 0xff);
}
} else {
hibyte <<= 8;
for (int i = count ; i-- > 0 ;) {
value[i] = (char) (hibyte | (ascii[i + offset] & 0xff));
}
}
this.offset = 0;
this.count = count;
this.value = value;
| public String(byte[] ascii, int hibyte)Allocates a new {@code String} containing characters constructed from
an array of 8-bit integer values. Each character cin the
resulting string is constructed from the corresponding component
b in the byte array such that:
c == (char)(((hibyte & 0xff) << 8)
| (b & 0xff))
this(ascii, hibyte, 0, ascii.length);
| public String(byte[] bytes, int offset, int length, String charsetName)Constructs a new {@code String} by decoding the specified subarray of
bytes using the specified charset. The length of the new {@code String}
is a function of the charset, and hence may not be equal to the length
of the subarray.
The behavior of this constructor when the given bytes are not valid
in the given charset is unspecified. The {@link
java.nio.charset.CharsetDecoder} class should be used when more control
over the decoding process is required.
if (charsetName == null)
throw new NullPointerException("charsetName");
checkBounds(bytes, offset, length);
char[] v = StringCoding.decode(charsetName, bytes, offset, length);
this.offset = 0;
this.count = v.length;
this.value = v;
|
| Methods Summary |
|---|
| public char | charAt(int index)Returns the char value at the
specified index. An index ranges from 0 to
length() - 1. The first char value of the sequence
is at index 0, the next at index 1,
and so on, as for array indexing.
If the char value specified by the index is a
surrogate, the surrogate
value is returned.
if ((index < 0) || (index >= count)) {
throw new StringIndexOutOfBoundsException(index);
}
return value[index + offset];
| | private static void | checkBounds(byte[] bytes, int offset, int length)
if (length < 0)
throw new StringIndexOutOfBoundsException(length);
if (offset < 0)
throw new StringIndexOutOfBoundsException(offset);
if (offset > bytes.length - length)
throw new StringIndexOutOfBoundsException(offset + length);
| | public int | codePointAt(int index)Returns the character (Unicode code point) at the specified
index. The index refers to char values
(Unicode code units) and ranges from 0 to
{@link #length()} - 1.
If the char value specified at the given index
is in the high-surrogate range, the following index is less
than the length of this String, and the
char value at the following index is in the
low-surrogate range, then the supplementary code point
corresponding to this surrogate pair is returned. Otherwise,
the char value at the given index is returned.
if ((index < 0) || (index >= count)) {
throw new StringIndexOutOfBoundsException(index);
}
return Character.codePointAtImpl(value, offset + index, offset + count);
| | public int | codePointBefore(int index)Returns the character (Unicode code point) before the specified
index. The index refers to char values
(Unicode code units) and ranges from 1 to {@link
CharSequence#length() length}.
If the char value at (index - 1)
is in the low-surrogate range, (index - 2) is not
negative, and the char value at (index -
2) is in the high-surrogate range, then the
supplementary code point value of the surrogate pair is
returned. If the char value at index -
1 is an unpaired low-surrogate or a high-surrogate, the
surrogate value is returned.
int i = index - 1;
if ((i < 0) || (i >= count)) {
throw new StringIndexOutOfBoundsException(index);
}
return Character.codePointBeforeImpl(value, offset + index, offset);
| | public int | codePointCount(int beginIndex, int endIndex)Returns the number of Unicode code points in the specified text
range of this String. The text range begins at the
specified beginIndex and extends to the
char at index endIndex - 1. Thus the
length (in chars) of the text range is
endIndex-beginIndex. Unpaired surrogates within
the text range count as one code point each.
if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
throw new IndexOutOfBoundsException();
}
return Character.codePointCountImpl(value, offset+beginIndex, endIndex-beginIndex);
| | public int | compareTo(java.lang.String anotherString)Compares two strings lexicographically.
The comparison is based on the Unicode value of each character in
the strings. The character sequence represented by this
String object is compared lexicographically to the
character sequence represented by the argument string. The result is
a negative integer if this String object
lexicographically precedes the argument string. The result is a
positive integer if this String object lexicographically
follows the argument string. The result is zero if the strings
are equal; compareTo returns 0 exactly when
the {@link #equals(Object)} method would return true.
This is the definition of lexicographic ordering. If two strings are
different, then either they have different characters at some index
that is a valid index for both strings, or their lengths are different,
or both. If they have different characters at one or more index
positions, let k be the smallest such index; then the string
whose character at position k has the smaller value, as
determined by using the < operator, lexicographically precedes the
other string. In this case, compareTo returns the
difference of the two character values at position k in
the two string -- that is, the value:
this.charAt(k)-anotherString.charAt(k)
If there is no index position at which they differ, then the shorter
string lexicographically precedes the longer string. In this case,
compareTo returns the difference of the lengths of the
strings -- that is, the value:
this.length()-anotherString.length()
int len1 = count;
int len2 = anotherString.count;
int n = Math.min(len1, len2);
char v1[] = value;
char v2[] = anotherString.value;
int i = offset;
int j = anotherString.offset;
if (i == j) {
int k = i;
int lim = n + i;
while (k < lim) {
char c1 = v1[k];
char c2 = v2[k];
if (c1 != c2) {
return c1 - c2;
}
k++;
}
} else {
while (n-- != 0) {
char c1 = v1[i++];
char c2 = v2[j++];
if (c1 != c2) {
return c1 - c2;
}
}
}
return len1 - len2;
| | public int | compareToIgnoreCase(java.lang.String str)Compares two strings lexicographically, ignoring case
differences. This method returns an integer whose sign is that of
calling compareTo with normalized versions of the strings
where case differences have been eliminated by calling
Character.toLowerCase(Character.toUpperCase(character)) on
each character.
Note that this method does not take locale into account,
and will result in an unsatisfactory ordering for certain locales.
The java.text package provides collators to allow
locale-sensitive ordering.
return CASE_INSENSITIVE_ORDER.compare(this, str);
| | public java.lang.String | concat(java.lang.String str)Concatenates the specified string to the end of this string.
If the length of the argument string is 0, then this
String object is returned. Otherwise, a new
String object is created, representing a character
sequence that is the concatenation of the character sequence
represented by this String object and the character
sequence represented by the argument string.
Examples:
"cares".concat("s") returns "caress"
"to".concat("get").concat("her") returns "together"
int otherLen = str.length();
if (otherLen == 0) {
return this;
}
char buf[] = new char[count + otherLen];
getChars(0, count, buf, 0);
str.getChars(0, otherLen, buf, count);
return new String(0, count + otherLen, buf);
| | public boolean | contains(java.lang.CharSequence s)Returns true if and only if this string contains the specified
sequence of char values.
return indexOf(s.toString()) > -1;
| | public boolean | contentEquals(java.lang.StringBuffer sb)Compares this string to the specified {@code StringBuffer}. The result
is {@code true} if and only if this {@code String} represents the same
sequence of characters as the specified {@code StringBuffer}.
synchronized(sb) {
return contentEquals((CharSequence)sb);
}
| | public boolean | contentEquals(java.lang.CharSequence cs)Compares this string to the specified {@code CharSequence}. The result
is {@code true} if and only if this {@code String} represents the same
sequence of char values as the specified sequence.
if (count != cs.length())
return false;
// Argument is a StringBuffer, StringBuilder
if (cs instanceof AbstractStringBuilder) {
char v1[] = value;
char v2[] = ((AbstractStringBuilder)cs).getValue();
int i = offset;
int j = 0;
int n = count;
while (n-- != 0) {
if (v1[i++] != v2[j++])
return false;
}
}
// Argument is a String
if (cs.equals(this))
return true;
// Argument is a generic CharSequence
char v1[] = value;
int i = offset;
int j = 0;
int n = count;
while (n-- != 0) {
if (v1[i++] != cs.charAt(j++))
return false;
}
return true;
| | public static java.lang.String | copyValueOf(char[] data, int offset, int count)Returns a String that represents the character sequence in the
array specified.
// All public String constructors now copy the data.
return new String(data, offset, count);
| | public static java.lang.String | copyValueOf(char[] data)Returns a String that represents the character sequence in the
array specified.
return copyValueOf(data, 0, data.length);
| | public boolean | endsWith(java.lang.String suffix)Tests if this string ends with the specified suffix.
return startsWith(suffix, count - suffix.count);
| | public boolean | equals(java.lang.Object anObject)Compares this string to the specified object. The result is {@code
true} if and only if the argument is not {@code null} and is a {@code
String} object that represents the same sequence of characters as this
object.
if (this == anObject) {
return true;
}
if (anObject instanceof String) {
String anotherString = (String)anObject;
int n = count;
if (n == anotherString.count) {
char v1[] = value;
char v2[] = anotherString.value;
int i = offset;
int j = anotherString.offset;
while (n-- != 0) {
if (v1[i++] != v2[j++])
return false;
}
return true;
}
}
return false;
| | public boolean | equalsIgnoreCase(java.lang.String anotherString)Compares this {@code String} to another {@code String}, ignoring case
considerations. Two strings are considered equal ignoring case if they
are of the same length and corresponding characters in the two strings
are equal ignoring case.
Two characters {@code c1} and {@code c2} are considered the same
ignoring case if at least one of the following is true:
- The two characters are the same (as compared by the
{@code ==} operator)
- Applying the method {@link
java.lang.Character#toUpperCase(char)} to each character
produces the same result
- Applying the method {@link
java.lang.Character#toLowerCase(char)} to each character
produces the same result
return (this == anotherString) ? true :
(anotherString != null) && (anotherString.count == count) &&
regionMatches(true, 0, anotherString, 0, count);
| | public static java.lang.String | format(java.lang.String format, java.lang.Object args)Returns a formatted string using the specified format string and
arguments.
The locale always used is the one returned by {@link
java.util.Locale#getDefault() Locale.getDefault()}.
return new Formatter().format(format, args).toString();
| | public static java.lang.String | format(java.util.Locale l, java.lang.String format, java.lang.Object args)Returns a formatted string using the specified locale, format string,
and arguments.
return new Formatter(l).format(format, args).toString();
| | public void | getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin)Copies characters from this string into the destination byte array. Each
byte receives the 8 low-order bits of the corresponding character. The
eight high-order bits of each character are not copied and do not
participate in the transfer in any way.
The first character to be copied is at index {@code srcBegin}; the
last character to be copied is at index {@code srcEnd-1}. The total
number of characters to be copied is {@code srcEnd-srcBegin}. The
characters, converted to bytes, are copied into the subarray of {@code
dst} starting at index {@code dstBegin} and ending at index:
dstbegin + (srcEnd-srcBegin) - 1
if (srcBegin < 0) {
throw new StringIndexOutOfBoundsException(srcBegin);
}
if (srcEnd > count) {
throw new StringIndexOutOfBoundsException(srcEnd);
}
if (srcBegin > srcEnd) {
throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
}
int j = dstBegin;
int n = offset + srcEnd;
int i = offset + srcBegin;
char[] val = value; /* avoid getfield opcode */
while (i < n) {
dst[j++] = (byte)val[i++];
}
| | public byte[] | getBytes(java.lang.String charsetName)Encodes this {@code String} into a sequence of bytes using the named
charset, storing the result into a new byte array.
The behavior of this method when this string cannot be encoded in
the given charset is unspecified. The {@link
java.nio.charset.CharsetEncoder} class should be used when more control
over the encoding process is required.
if (charsetName == null) throw new NullPointerException();
return StringCoding.encode(charsetName, value, offset, count);
| | public byte[] | getBytes(java.nio.charset.Charset charset)Encodes this {@code String} into a sequence of bytes using the given
{@linkplain java.nio.charset.Charset charset}, storing the result into a
new byte array.
This method always replaces malformed-input and unmappable-character
sequences with this charset's default replacement byte array. The
{@link java.nio.charset.CharsetEncoder} class should be used when more
control over the encoding process is required.
if (charset == null) throw new NullPointerException();
return StringCoding.encode(charset, value, offset, count);
| | public byte[] | getBytes()Encodes this {@code String} into a sequence of bytes using the
platform's default charset, storing the result into a new byte array.
The behavior of this method when this string cannot be encoded in
the default charset is unspecified. The {@link
java.nio.charset.CharsetEncoder} class should be used when more control
over the encoding process is required.
return StringCoding.encode(value, offset, count);
| | void | getChars(char[] dst, int dstBegin)Copy characters from this string into dst starting at dstBegin.
This method doesn't perform any range checking.
System.arraycopy(value, offset, dst, dstBegin, count);
| | public void | getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)Copies characters from this string into the destination character
array.
The first character to be copied is at index srcBegin;
the last character to be copied is at index srcEnd-1
(thus the total number of characters to be copied is
srcEnd-srcBegin). The characters are copied into the
subarray of dst starting at index dstBegin
and ending at index:
dstbegin + (srcEnd-srcBegin) - 1
if (srcBegin < 0) {
throw new StringIndexOutOfBoundsException(srcBegin);
}
if (srcEnd > count) {
throw new StringIndexOutOfBoundsException(srcEnd);
}
if (srcBegin > srcEnd) {
throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
}
System.arraycopy(value, offset + srcBegin, dst, dstBegin,
srcEnd - srcBegin);
| | public int | hashCode()Returns a hash code for this string. The hash code for a
String object is computed as
s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
using int arithmetic, where s[i] is the
ith character of the string, n is the length of
the string, and ^ indicates exponentiation.
(The hash value of the empty string is zero.)
int h = hash;
if (h == 0) {
int off = offset;
char val[] = value;
int len = count;
for (int i = 0; i < len; i++) {
h = 31*h + val[off++];
}
hash = h;
}
return h;
| | public int | indexOf(int ch)Returns the index within this string of the first occurrence of
the specified character. If a character with value
ch occurs in the character sequence represented by
this String object, then the index (in Unicode
code units) of the first such occurrence is returned. For
values of ch in the range from 0 to 0xFFFF
(inclusive), this is the smallest value k such that:
this.charAt(k) == ch
is true. For other values of ch, it is the
smallest value k such that:
this.codePointAt(k) == ch
is true. In either case, if no such character occurs in this
string, then -1 is returned.
return indexOf(ch, 0);
| | public int | indexOf(int ch, int fromIndex)Returns the index within this string of the first occurrence of the
specified character, starting the search at the specified index.
If a character with value ch occurs in the
character sequence represented by this String
object at an index no smaller than fromIndex, then
the index of the first such occurrence is returned. For values
of ch in the range from 0 to 0xFFFF (inclusive),
this is the smallest value k such that:
(this.charAt(k) == ch) && (k >= fromIndex)
is true. For other values of ch, it is the
smallest value k such that:
(this.codePointAt(k) == ch) && (k >= fromIndex)
is true. In either case, if no such character occurs in this
string at or after position fromIndex, then
-1 is returned.
There is no restriction on the value of fromIndex. If it
is negative, it has the same effect as if it were zero: this entire
string may be searched. If it is greater than the length of this
string, it has the same effect as if it were equal to the length of
this string: -1 is returned.
All indices are specified in char values
(Unicode code units).
int max = offset + count;
char v[] = value;
if (fromIndex < 0) {
fromIndex = 0;
} else if (fromIndex >= count) {
// Note: fromIndex might be near -1>>>1.
return -1;
}
int i = offset + fromIndex;
if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
// handle most cases here (ch is a BMP code point or a
// negative value (invalid code point))
for (; i < max ; i++) {
if (v[i] == ch) {
return i - offset;
}
}
return -1;
}
if (ch <= Character.MAX_CODE_POINT) {
// handle supplementary characters here
char[] surrogates = Character.toChars(ch);
for (; i < max; i++) {
if (v[i] == surrogates[0]) {
if (i + 1 == max) {
break;
}
if (v[i+1] == surrogates[1]) {
return i - offset;
}
}
}
}
return -1;
| | public int | indexOf(java.lang.String str)Returns the index within this string of the first occurrence of the
specified substring. The integer returned is the smallest value
k such that:
this.startsWith(str, k)
is true.
return indexOf(str, 0);
| | public int | indexOf(java.lang.String str, int fromIndex)Returns the index within this string of the first occurrence of the
specified substring, starting at the specified index. The integer
returned is the smallest value k for which:
k >= Math.min(fromIndex, this.length()) && this.startsWith(str, k)
If no such value of k exists, then -1 is returned.
return indexOf(value, offset, count,
str.value, str.offset, str.count, fromIndex);
| | static int | indexOf(char[] source, int sourceOffset, int sourceCount, char[] target, int targetOffset, int targetCount, int fromIndex)Code shared by String and StringBuffer to do searches. The
source is the character array being searched, and the target
is the string being searched for.
if (fromIndex >= sourceCount) {
return (targetCount == 0 ? sourceCount : -1);
}
if (fromIndex < 0) {
fromIndex = 0;
}
if (targetCount == 0) {
return fromIndex;
}
char first = target[targetOffset];
int max = sourceOffset + (sourceCount - targetCount);
for (int i = sourceOffset + fromIndex; i <= max; i++) {
/* Look for first character. */
if (source[i] != first) {
while (++i <= max && source[i] != first);
}
/* Found first character, now look at the rest of v2 */
if (i <= max) {
int j = i + 1;
int end = j + targetCount - 1;
for (int k = targetOffset + 1; j < end && source[j] ==
target[k]; j++, k++);
if (j == end) {
/* Found whole string. */
return i - sourceOffset;
}
}
}
return -1;
| | public native java.lang.String | intern()Returns a canonical representation for the string object.
A pool of strings, initially empty, is maintained privately by the
class String.
When the intern method is invoked, if the pool already contains a
string equal to this String object as determined by
the {@link #equals(Object)} method, then the string from the pool is
returned. Otherwise, this String object is added to the
pool and a reference to this String object is returned.
It follows that for any two strings s and t,
s.intern() == t.intern() is true
if and only if s.equals(t) is true.
All literal strings and string-valued constant expressions are
interned. String literals are defined in §3.10.5 of the
Java Language
Specification
| | public boolean | isEmpty()Returns true if, and only if, {@link #length()} is 0.
return count == 0;
| | public int | lastIndexOf(int ch)Returns the index within this string of the last occurrence of
the specified character. For values of ch in the
range from 0 to 0xFFFF (inclusive), the index (in Unicode code
units) returned is the largest value k such that:
this.charAt(k) == ch
is true. For other values of ch, it is the
largest value k such that:
this.codePointAt(k) == ch
is true. In either case, if no such character occurs in this
string, then -1 is returned. The
String is searched backwards starting at the last
character.
return lastIndexOf(ch, count - 1);
| | public int | lastIndexOf(int ch, int fromIndex)Returns the index within this string of the last occurrence of
the specified character, searching backward starting at the
specified index. For values of ch in the range
from 0 to 0xFFFF (inclusive), the index returned is the largest
value k such that:
(this.charAt(k) == ch) && (k <= fromIndex)
is true. For other values of ch, it is the
largest value k such that:
(this.codePointAt(k) == ch) && (k <= fromIndex)
is true. In either case, if no such character occurs in this
string at or before position fromIndex, then
-1 is returned.
All indices are specified in char values
(Unicode code units).
int min = offset;
char v[] = value;
int i = offset + ((fromIndex >= count) ? count - 1 : fromIndex);
if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
// handle most cases here (ch is a BMP code point or a
// negative value (invalid code point))
for (; i >= min ; i--) {
if (v[i] == ch) {
return i - offset;
}
}
return -1;
}
int max = offset + count;
if (ch <= Character.MAX_CODE_POINT) {
// handle supplementary characters here
char[] surrogates = Character.toChars(ch);
for (; i >= min; i--) {
if (v[i] == surrogates[0]) {
if (i + 1 == max) {
break;
}
if (v[i+1] == surrogates[1]) {
return i - offset;
}
}
}
}
return -1;
| | public int | lastIndexOf(java.lang.String str)Returns the index within this string of the rightmost occurrence
of the specified substring. The rightmost empty string "" is
considered to occur at the index value this.length().
The returned index is the largest value k such that
this.startsWith(str, k)
is true.
return lastIndexOf(str, count);
| | public int | lastIndexOf(java.lang.String str, int fromIndex)Returns the index within this string of the last occurrence of the
specified substring, searching backward starting at the specified index.
The integer returned is the largest value k such that:
k <= Math.min(fromIndex, this.length()) && this.startsWith(str, k)
If no such value of k exists, then -1 is returned.
return lastIndexOf(value, offset, count,
str.value, str.offset, str.count, fromIndex);
| | static int | lastIndexOf(char[] source, int sourceOffset, int sourceCount, char[] target, int targetOffset, int targetCount, int fromIndex)Code shared by String and StringBuffer to do searches. The
source is the character array being searched, and the target
is the string being searched for.
/*
* Check arguments; return immediately where possible. For
* consistency, don't check for null str.
*/
int rightIndex = sourceCount - targetCount;
if (fromIndex < 0) {
return -1;
}
if (fromIndex > rightIndex) {
fromIndex = rightIndex;
}
/* Empty string always matches. */
if (targetCount == 0) {
return fromIndex;
}
int strLastIndex = targetOffset + targetCount - 1;
char strLastChar = target[strLastIndex];
int min = sourceOffset + targetCount - 1;
int i = min + fromIndex;
startSearchForLastChar:
while (true) {
while (i >= min && source[i] != strLastChar) {
i--;
}
if (i < min) {
return -1;
}
int j = i - 1;
int start = j - (targetCount - 1);
int k = strLastIndex - 1;
while (j > start) {
if (source[j--] != target[k--]) {
i--;
continue startSearchForLastChar;
}
}
return start - sourceOffset + 1;
}
| | public int | length()Returns the length of this string.
The length is equal to the number of Unicode
code units in the string.
return count;
| | public boolean | matches(java.lang.String regex)Tells whether or not this string matches the given regular expression.
An invocation of this method of the form
str.matches(regex) yields exactly the
same result as the expression
{@link java.util.regex.Pattern}.{@link
java.util.regex.Pattern#matches(String,CharSequence)
matches}(regex, str)
return Pattern.matches(regex, this);
| | public int | offsetByCodePoints(int index, int codePointOffset)Returns the index within this String that is
offset from the given index by
codePointOffset code points. Unpaired surrogates
within the text range given by index and
codePointOffset count as one code point each.
if (index < 0 || index > count) {
throw new IndexOutOfBoundsException();
}
return Character.offsetByCodePointsImpl(value, offset, count,
offset+index, codePointOffset) - offset;
| | public boolean | regionMatches(int toffset, java.lang.String other, int ooffset, int len)Tests if two string regions are equal.
A substring of this String object is compared to a substring
of the argument other. The result is true if these substrings
represent identical character sequences. The substring of this
String object to be compared begins at index toffset
and has length len. The substring of other to be compared
begins at index ooffset and has length len. The
result is false if and only if at least one of the following
is true:
- toffset is negative.
- ooffset is negative.
- toffset+len is greater than the length of this
String object.
- ooffset+len is greater than the length of the other
argument.
- There is some nonnegative integer k less than len
such that:
this.charAt(toffset+k) != other.charAt(ooffset+k)
char ta[] = value;
int to = offset + toffset;
char pa[] = other.value;
int po = other.offset + ooffset;
// Note: toffset, ooffset, or len might be near -1>>>1.
if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len)
|| (ooffset > (long)other.count - len)) {
return false;
}
while (len-- > 0) {
if (ta[to++] != pa[po++]) {
return false;
}
}
return true;
| | public boolean | regionMatches(boolean ignoreCase, int toffset, java.lang.String other, int ooffset, int len)Tests if two string regions are equal.
A substring of this String object is compared to a substring
of the argument other. The result is true if these
substrings represent character sequences that are the same, ignoring
case if and only if ignoreCase is true. The substring of
this String object to be compared begins at index
toffset and has length len. The substring of
other to be compared begins at index ooffset and
has length len. The result is false if and only if
at least one of the following is true:
- toffset is negative.
- ooffset is negative.
- toffset+len is greater than the length of this
String object.
- ooffset+len is greater than the length of the other
argument.
- ignoreCase is false and there is some nonnegative
integer k less than len such that:
this.charAt(toffset+k) != other.charAt(ooffset+k)
- ignoreCase is true and there is some nonnegative
integer k less than len such that:
Character.toLowerCase(this.charAt(toffset+k)) !=
Character.toLowerCase(other.charAt(ooffset+k))
and:
Character.toUpperCase(this.charAt(toffset+k)) !=
Character.toUpperCase(other.charAt(ooffset+k))
char ta[] = value;
int to = offset + toffset;
char pa[] = other.value;
int po = other.offset + ooffset;
// Note: toffset, ooffset, or len might be near -1>>>1.
if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) ||
(ooffset > (long)other.count - len)) {
return false;
}
while (len-- > 0) {
char c1 = ta[to++];
char c2 = pa[po++];
if (c1 == c2) {
continue;
}
if (ignoreCase) {
// If characters don't match but case may be ignored,
// try converting both characters to uppercase.
// If the results match, then the comparison scan should
// continue.
char u1 = Character.toUpperCase(c1);
char u2 = Character.toUpperCase(c2);
if (u1 == u2) {
continue;
}
// Unfortunately, conversion to uppercase does not work properly
// for the Georgian alphabet, which has strange rules about case
// conversion. So we need to make one last check before
// exiting.
if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
continue;
}
}
return false;
}
return true;
| | public java.lang.String | replace(char oldChar, char newChar)Returns a new string resulting from replacing all occurrences of
oldChar in this string with newChar.
If the character oldChar does not occur in the
character sequence represented by this String object,
then a reference to this String object is returned.
Otherwise, a new String object is created that
represents a character sequence identical to the character sequence
represented by this String object, except that every
occurrence of oldChar is replaced by an occurrence
of newChar.
Examples:
"mesquite in your cellar".replace('e', 'o')
returns "mosquito in your collar"
"the war of baronets".replace('r', 'y')
returns "the way of bayonets"
"sparring with a purple porpoise".replace('p', 't')
returns "starring with a turtle tortoise"
"JonL".replace('q', 'x') returns "JonL" (no change)
if (oldChar != newChar) {
int len = count;
int i = -1;
char[] val = value; /* avoid getfield opcode */
int off = offset; /* avoid getfield opcode */
while (++i < len) {
if (val[off + i] == oldChar) {
break;
}
}
if (i < len) {
char buf[] = new char[len];
for (int j = 0 ; j < i ; j++) {
buf[j] = val[off+j];
}
while (i < len) {
char c = val[off + i];
buf[i] = (c == oldChar) ? newChar : c;
i++;
}
return new String(0, len, buf);
}
}
return this;
| | public java.lang.String | replace(java.lang.CharSequence target, java.lang.CharSequence replacement)Replaces each substring of this string that matches the literal target
sequence with the specified literal replacement sequence. The
replacement proceeds from the beginning of the string to the end, for
example, replacing "aa" with "b" in the string "aaa" will result in
"ba" rather than "ab".
return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
| | public java.lang.String | replaceAll(java.lang.String regex, java.lang.String replacement)Replaces each substring of this string that matches the given regular expression with the
given replacement.
An invocation of this method of the form
str.replaceAll(regex, repl)
yields exactly the same result as the expression
{@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
compile}(regex).{@link
java.util.regex.Pattern#matcher(java.lang.CharSequence)
matcher}(str).{@link java.util.regex.Matcher#replaceAll
replaceAll}(repl)
Note that backslashes (\) and dollar signs ($) in the
replacement string may cause the results to be different than if it were
being treated as a literal replacement string; see
{@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
meaning of these characters, if desired.
return Pattern.compile(regex).matcher(this).replaceAll(replacement);
| | public java.lang.String | replaceFirst(java.lang.String regex, java.lang.String replacement)Replaces the first substring of this string that matches the given regular expression with the
given replacement.
An invocation of this method of the form
str.replaceFirst(regex, repl)
yields exactly the same result as the expression
{@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
compile}(regex).{@link
java.util.regex.Pattern#matcher(java.lang.CharSequence)
matcher}(str).{@link java.util.regex.Matcher#replaceFirst
replaceFirst}(repl)
Note that backslashes (\) and dollar signs ($) in the
replacement string may cause the results to be different than if it were
being treated as a literal replacement string; see
{@link java.util.regex.Matcher#replaceFirst}.
Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
meaning of these characters, if desired.
return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
| | public java.lang.String[] | split(java.lang.String regex, int limit)Splits this string around matches of the given
regular expression.
The array returned by this method contains each substring of this
string that is terminated by another substring that matches the given
expression or is terminated by the end of the string. The substrings in
the array are in the order in which they occur in this string. If the
expression does not match any part of the input then the resulting array
has just one element, namely this string.
The limit parameter controls the number of times the
pattern is applied and therefore affects the length of the resulting
array. If the limit n is greater than zero then the pattern
will be applied at most n - 1 times, the array's
length will be no greater than n, and the array's last entry
will contain all input beyond the last matched delimiter. If n
is non-positive then the pattern will be applied as many times as
possible and the array can have any length. If n is zero then
the pattern will be applied as many times as possible, the array can
have any length, and trailing empty strings will be discarded.
The string "boo:and:foo", for example, yields the
following results with these parameters:
| Regex |
Limit |
Result |
| : |
2 |
{ "boo", "and:foo" } |
| : |
5 |
{ "boo", "and", "foo" } |
| : |
-2 |
{ "boo", "and", "foo" } |
| o |
5 |
{ "b", "", ":and:f", "", "" } |
| o |
-2 |
{ "b", "", ":and:f", "", "" } |
| o |
0 |
{ "b", "", ":and:f" } |
An invocation of this method of the form
str.split(regex, n)
yields the same result as the expression
{@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
compile}(regex).{@link
java.util.regex.Pattern#split(java.lang.CharSequence,int)
split}(str, n)
return Pattern.compile(regex).split(this, limit);
| | public java.lang.String[] | split(java.lang.String regex)Splits this string around matches of the given regular expression.
This method works as if by invoking the two-argument {@link
#split(String, int) split} method with the given expression and a limit
argument of zero. Trailing empty strings are therefore not included in
the resulting array.
The string "boo:and:foo", for example, yields the following
results with these expressions:
| Regex |
Result |
| : |
{ "boo", "and", "foo" } |
| o |
{ "b", "", ":and:f" } |
return split(regex, 0);
| | public boolean | startsWith(java.lang.String prefix, int toffset)Tests if the substring of this string beginning at the
specified index starts with the specified prefix.
char ta[] = value;
int to = offset + toffset;
char pa[] = prefix.value;
int po = prefix.offset;
int pc = prefix.count;
// Note: toffset might be near -1>>>1.
if ((toffset < 0) || (toffset > count - pc)) {
return false;
}
while (--pc >= 0) {
if (ta[to++] != pa[po++]) {
return false;
}
}
return true;
| | public boolean | startsWith(java.lang.String prefix)Tests if this string starts with the specified prefix.
return startsWith(prefix, 0);
| | public java.lang.CharSequence | subSequence(int beginIndex, int endIndex)Returns a new character sequence that is a subsequence of this sequence.
An invocation of this method of the form
str.subSequence(begin, end)
behaves in exactly the same way as the invocation
str.substring(begin, end)
This method is defined so that the String class can implement
the {@link CharSequence} interface.
return this.substring(beginIndex, endIndex);
| | public java.lang.String | substring(int beginIndex)Returns a new string that is a substring of this string. The
substring begins with the character at the specified index and
extends to the end of this string.
Examples:
"unhappy".substring(2) returns "happy"
"Harbison".substring(3) returns "bison"
"emptiness".substring(9) returns "" (an empty string)
return substring(beginIndex, count);
| | public java.lang.String | substring(int beginIndex, int endIndex)Returns a new string that is a substring of this string. The
substring begins at the specified beginIndex and
extends to the character at index endIndex - 1.
Thus the length of the substring is endIndex-beginIndex.
Examples:
"hamburger".substring(4, 8) returns "urge"
"smiles".substring(1, 5) returns "mile"
if (beginIndex < 0) {
throw new StringIndexOutOfBoundsException(beginIndex);
}
if (endIndex > count) {
throw new StringIndexOutOfBoundsException(endIndex);
}
if (beginIndex > endIndex) {
throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
}
return ((beginIndex == 0) && (endIndex == count)) ? this :
new String(offset + beginIndex, endIndex - beginIndex, value);
| | public char[] | toCharArray()Converts this string to a new character array.
char result[] = new char[count];
getChars(0, count, result, 0);
return result;
| | public java.lang.String | toLowerCase(java.util.Locale locale)Converts all of the characters in this String to lower
case using the rules of the given Locale. Case mapping is based
on the Unicode Standard version specified by the {@link java.lang.Character Character}
class. Since case mappings are not always 1:1 char mappings, the resulting
String may be a different length than the original String.
Examples of lowercase mappings are in the following table:
| Language Code of Locale |
Upper Case |
Lower Case |
Description |
| tr (Turkish) |
\u0130 |
\u0069 |
capital letter I with dot above -> small letter i |
| tr (Turkish) |
\u0049 |
\u0131 |
capital letter I -> small letter dotless i |
| (all) |
French Fries |
french fries |
lowercased all chars in String |
| (all) |
 
 
 |
 
 
 |
lowercased all chars in String |
if (locale == null) {
throw new NullPointerException();
}
int firstUpper;
/* Now check if there are any characters that need to be changed. */
scan: {
for (firstUpper = 0 ; firstUpper < count; ) {
char c = value[offset+firstUpper];
if ((c >= Character.MIN_HIGH_SURROGATE) &&
(c <= Character.MAX_HIGH_SURROGATE)) {
int supplChar = codePointAt(firstUpper);
if (supplChar != Character.toLowerCase(supplChar)) {
break scan;
}
firstUpper += Character.charCount(supplChar);
} else {
if (c != Character.toLowerCase(c)) {
break scan;
}
firstUpper++;
}
}
return this;
}
char[] result = new char[count];
int resultOffset = 0; /* result may grow, so i+resultOffset
* is the write location in result */
/* Just copy the first few lowerCase characters. */
System.arraycopy(value, offset, result, 0, firstUpper);
String lang = locale.getLanguage();
boolean localeDependent =
(lang == "tr" || lang == "az" || lang == "lt");
char[] lowerCharArray;
int lowerChar;
int srcChar;
int srcCount;
for (int i = firstUpper; i < count; i += srcCount) {
srcChar = (int)value[offset+i];
if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
(char)srcChar <= Character.MAX_HIGH_SURROGATE) {
srcChar = codePointAt(i);
srcCount = Character.charCount(srcChar);
} else {
srcCount = 1;
}
if (localeDependent || srcChar == '\u03A3") { // GREEK CAPITAL LETTER SIGMA
lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
} else {
lowerChar = Character.toLowerCase(srcChar);
}
if ((lowerChar == Character.ERROR) ||
(lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
if (lowerChar == Character.ERROR) {
lowerCharArray =
ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
} else if (srcCount == 2) {
resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
continue;
} else {
lowerCharArray = Character.toChars(lowerChar);
}
/* Grow result if needed */
int mapLen = lowerCharArray.length;
if (mapLen > srcCount) {
char[] result2 = new char[result.length + mapLen - srcCount];
System.arraycopy(result, 0, result2, 0,
i + resultOffset);
result = result2;
}
for (int x=0; x<mapLen; ++x) {
result[i+resultOffset+x] = lowerCharArray[x];
}
resultOffset += (mapLen - srcCount);
} else {
result[i+resultOffset] = (char)lowerChar;
}
}
return new String(0, count+resultOffset, result);
| | public java.lang.String | toLowerCase()Converts all of the characters in this String to lower
case using the rules of the default locale. This is equivalent to calling
toLowerCase(Locale.getDefault()).
Note: This method is locale sensitive, and may produce unexpected
results if used for strings that are intended to be interpreted locale
independently.
Examples are programming language identifiers, protocol keys, and HTML
tags.
For instance, "TITLE".toLowerCase() in a Turkish locale
returns "t\u0131tle", where '\u0131' is the LATIN SMALL
LETTER DOTLESS I character.
To obtain correct results for locale insensitive strings, use
toLowerCase(Locale.ENGLISH).
return toLowerCase(Locale.getDefault());
| | public java.lang.String | toString()This object (which is already a string!) is itself returned.
return this;
| | public java.lang.String | toUpperCase(java.util.Locale locale)Converts all of the characters in this String to upper
case using the rules of the given Locale. Case mapping is based
on the Unicode Standard version specified by the {@link java.lang.Character Character}
class. Since case mappings are not always 1:1 char mappings, the resulting
String may be a different length than the original String.
Examples of locale-sensitive and 1:M case mappings are in the following table.
| Language Code of Locale |
Lower Case |
Upper Case |
Description |
| tr (Turkish) |
\u0069 |
\u0130 |
small letter i -> capital letter I with dot above |
| tr (Turkish) |
\u0131 |
\u0049 |
small letter dotless i -> capital letter I |
| (all) |
\u00df |
\u0053 \u0053 |
small letter sharp s -> two letters: SS |
| (all) |
Fahrvergnügen |
FAHRVERGNÜGEN |
|
if (locale == null) {
throw new NullPointerException();
}
int firstLower;
/* Now check if there are any characters that need to be changed. */
scan: {
for (firstLower = 0 ; firstLower < count; ) {
int c = (int)value[offset+firstLower];
int srcCount;
if ((c >= Character.MIN_HIGH_SURROGATE) &&
(c <= Character.MAX_HIGH_SURROGATE)) {
c = codePointAt(firstLower);
srcCount = Character.charCount(c);
} else {
srcCount = 1;
}
int upperCaseChar = Character.toUpperCaseEx(c);
if ((upperCaseChar == Character.ERROR) ||
(c != upperCaseChar)) {
break scan;
}
firstLower += srcCount;
}
return this;
}
char[] result = new char[count]; /* may grow */
int resultOffset = 0; /* result may grow, so i+resultOffset
* is the write location in result */
/* Just copy the first few upperCase characters. */
System.arraycopy(value, offset, result, 0, firstLower);
String lang = locale.getLanguage();
boolean localeDependent =
(lang == "tr" || lang == "az" || lang == "lt");
char[] upperCharArray;
int upperChar;
int srcChar;
int srcCount;
for (int i = firstLower; i < count; i += srcCount) {
srcChar = (int)value[offset+i];
if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
(char)srcChar <= Character.MAX_HIGH_SURROGATE) {
srcChar = codePointAt(i);
srcCount = Character.charCount(srcChar);
} else {
srcCount = 1;
}
if (localeDependent) {
upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
} else {
upperChar = Character.toUpperCaseEx(srcChar);
}
if ((upperChar == Character.ERROR) ||
(upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
if (upperChar == Character.ERROR) {
if (localeDependent) {
upperCharArray =
ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
} else {
upperCharArray = Character.toUpperCaseCharArray(srcChar);
}
} else if (srcCount == 2) {
resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
continue;
} else {
upperCharArray = Character.toChars(upperChar);
}
/* Grow result if needed */
int mapLen = upperCharArray.length;
if (mapLen > srcCount) {
char[] result2 = new char[result.length + mapLen - srcCount];
System.arraycopy(result, 0, result2, 0,
i + resultOffset);
result = result2;
}
for (int x=0; x<mapLen; ++x) {
result[i+resultOffset+x] = upperCharArray[x];
}
resultOffset += (mapLen - srcCount);
} else {
result[i+resultOffset] = (char)upperChar;
}
}
return new String(0, count+resultOffset, result);
| | public java.lang.String | toUpperCase()Converts all of the characters in this String to upper
case using the rules of the default locale. This method is equivalent to
toUpperCase(Locale.getDefault()).
Note: This method is locale sensitive, and may produce unexpected
results if used for strings that are intended to be interpreted locale
independently.
Examples are programming language identifiers, protocol keys, and HTML
tags.
For instance, "title".toUpperCase() in a Turkish locale
returns "T\u0130TLE", where '\u0130' is the LATIN CAPITAL
LETTER I WITH DOT ABOVE character.
To obtain correct results for locale insensitive strings, use
toUpperCase(Locale.ENGLISH).
return toUpperCase(Locale.getDefault());
| | public java.lang.String | trim()Returns a copy of the string, with leading and trailing whitespace
omitted.
If this String object represents an empty character
sequence, or the first and last characters of character sequence
represented by this String object both have codes
greater than '\u0020' (the space character), then a
reference to this String object is returned.
Otherwise, if there is no character with a code greater than
'\u0020' in the string, then a new
String object representing an empty string is created
and returned.
Otherwise, let k be the index of the first character in the
string whose code is greater than '\u0020', and let
m be the index of the last character in the string whose code
is greater than '\u0020'. A new String
object is created, representing the substring of this string that
begins with the character at index k and ends with the
character at index m-that is, the result of
this.substring(k, m+1).
This method may be used to trim whitespace (as defined above) from
the beginning and end of a string.
int len = count;
int st = 0;
int off = offset; /* avoid getfield opcode */
char[] val = value; /* avoid getfield opcode */
while ((st < len) && (val[off + st] <= ' ")) {
st++;
}
while ((st < len) && (val[off + len - 1] <= ' ")) {
len--;
}
return ((st > 0) || (len < count)) ? substring(st, len) : this;
| | public static java.lang.String | valueOf(java.lang.Object obj)Returns the string representation of the Object argument.
return (obj == null) ? "null" : obj.toString();
| | public static java.lang.String | valueOf(char[] data)Returns the string representation of the char array
argument. The contents of the character array are copied; subsequent
modification of the character array does not affect the newly
created string.
return new String(data);
| | public static java.lang.String | valueOf(char[] data, int offset, int count)Returns the string representation of a specific subarray of the
char array argument.
The offset argument is the index of the first
character of the subarray. The count argument
specifies the length of the subarray. The contents of the subarray
are copied; subsequent modification of the character array does not
affect the newly created string.
return new String(data, offset, count);
| | public static java.lang.String | valueOf(boolean b)Returns the string representation of the boolean argument.
return b ? "true" : "false";
| | public static java.lang.String | valueOf(char c)Returns the string representation of the char
argument.
char data[] = {c};
return new String(0, 1, data);
| | public static java.lang.String | valueOf(int i)Returns the string representation of the int argument.
The representation is exactly the one returned by the
Integer.toString method of one argument.
return Integer.toString(i, 10);
| | public static java.lang.String | valueOf(long l)Returns the string representation of the long argument.
The representation is exactly the one returned by the
Long.toString method of one argument.
return Long.toString(l, 10);
| | public static java.lang.String | valueOf(float f)Returns the string representation of the float argument.
The representation is exactly the one returned by the
Float.toString method of one argument.
return Float.toString(f);
| | public static java.lang.String | valueOf(double d)Returns the string representation of the double argument.
The representation is exactly the one returned by the
Double.toString method of one argument.
return Double.toString(d);
|
|
