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FlexDoc/Javadoc 2.0 Demo Java Doc |
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 Character class.
The Java language provides special support for the string concatenation operator ( + ), and for conversion of other objects to strings. For additional information on string concatenation and conversion, see The Java Language Specification.
Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a 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).
Unless otherwise noted, methods for comparing Strings do not take locale into account. The Collator class provides methods for finer-grain, locale-sensitive String comparison.
Field Summary |
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static final Comparator<String> |
A Comparator that orders String objects as by
compareToIgnoreCase.
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Constructor Summary |
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String()
Initializes a newly created String object so that it represents
an empty character sequence.
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String(byte[] bytes)
Constructs a new String by decoding the specified array of bytes
using the platform's default charset.
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Constructs a new String by decoding the specified array of
bytes using the specified charset.
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String(byte[] ascii, int hibyte)
Deprecated. This method does not properly convert bytes into
characters.
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String(byte[] bytes, int offset, int length)
Constructs a new String by decoding the specified subarray of
bytes using the platform's default charset.
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Constructs a new String by decoding the specified subarray of
bytes using the specified charset.
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String(byte[] ascii, int hibyte, int offset, int count)
Deprecated. This method does not properly convert bytes into characters.
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Constructs a new String by decoding the specified subarray of
bytes using the specified charset.
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Constructs a new String by decoding the specified array of bytes
using the specified charset.
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String(char[] value)
Allocates a new String so that it represents the sequence of
characters currently contained in the character array argument.
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String(char[] value, int offset, int count)
Allocates a new String that contains characters from a subarray
of the character array argument.
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String(int[] codePoints, int offset, int count)
Allocates a new String that contains characters from a subarray
of the Unicode code point array
argument.
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Initializes a newly created 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.
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String(StringBuffer buffer)
Allocates a new string that contains the sequence of characters
currently contained in the string buffer argument.
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String(StringBuilder builder)
Allocates a new string that contains the sequence of characters
currently contained in the string builder argument.
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Method Summary |
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char |
charAt(int index)
Returns the char value at the
specified index.
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chars()
Returns a stream of int zero-extending the char values
from this sequence.
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int |
codePointAt(int index)
Returns the character (Unicode code point) at the specified
index.
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int |
codePointBefore(int index)
Returns the character (Unicode code point) before the specified
index.
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int |
codePointCount(int beginIndex, int endIndex)
Returns the number of Unicode code points in the specified text
range of this String.
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Returns a stream of code point values from this sequence.
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int |
Compares two strings lexicographically.
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int |
Compares two strings lexicographically, ignoring case
differences.
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Concatenates the specified string to the end of this string.
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boolean |
Returns true if and only if this string contains the specified
sequence of char values.
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boolean |
Compares this string to the specified CharSequence.
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boolean |
Compares this string to the specified StringBuffer.
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static String |
copyValueOf(char[] data)
Equivalent to valueOf(char[]).
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static String |
copyValueOf(char[] data, int offset, int count)
Equivalent to valueOf(char[], int, int).
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Returns an Optional containing the nominal descriptor for this
instance, which is the instance itself.
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boolean |
Tests if this string ends with the specified suffix.
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boolean |
Compares this string to the specified object.
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boolean |
equalsIgnoreCase(String anotherString)
Compares this String to another String, ignoring case
considerations.
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static String |
Returns a formatted string using the specified locale, format string,
and arguments.
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static String |
Returns a formatted string using the specified format string and
arguments.
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Formats using this string as the format string, and the supplied
arguments.
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byte[] |
getBytes()
Encodes this String into a sequence of bytes using the
platform's default charset, storing the result into a new byte array.
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byte[] |
Encodes this String into a sequence of bytes using the given
charset, storing the result into a
new byte array.
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void |
getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin)
Deprecated. This method does not properly convert characters into
bytes.
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byte[] |
Encodes this String into a sequence of bytes using the named
charset, storing the result into a new byte array.
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void |
getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
Copies characters from this string into the destination character
array.
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int |
hashCode()
Returns a hash code for this string.
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indent(int n)
Adjusts the indentation of each line of this string based on the value of
n, and normalizes line termination characters.
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int |
indexOf(int ch)
Returns the index within this string of the first occurrence of
the specified character.
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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.
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int |
Returns the index within this string of the first occurrence of the
specified substring.
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int |
Returns the index within this string of the first occurrence of the
specified substring, starting at the specified index.
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intern()
Returns a canonical representation for the string object.
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boolean |
isBlank()
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boolean |
isEmpty()
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static String |
Returns a new String composed of copies of the
CharSequence elements joined together with a copy of
the specified delimiter.
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static String |
Returns a new String composed of copies of the
CharSequence elements joined together with a copy of the
specified delimiter.
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int |
lastIndexOf(int ch)
Returns the index within this string of the last occurrence of
the specified character.
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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.
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int |
lastIndexOf(String str)
Returns the index within this string of the last occurrence of the
specified substring.
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int |
lastIndexOf(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.
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int |
length()
Returns the length of this string.
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lines()
Returns a stream of lines extracted from this string,
separated by line terminators.
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boolean |
Tells whether or not this string matches the given regular expression.
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int |
offsetByCodePoints(int index, int codePointOffset)
Returns the index within this String that is
offset from the given index by
codePointOffset code points.
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boolean |
regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)
Tests if two string regions are equal.
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boolean |
regionMatches(int toffset, String other, int ooffset, int len)
Tests if two string regions are equal.
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repeat(int count)
Returns a string whose value is the concatenation of this
string repeated count times.
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replace(char oldChar, char newChar)
Returns a string resulting from replacing all occurrences of
oldChar in this string with newChar.
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Replaces each substring of this string that matches the literal target
sequence with the specified literal replacement sequence.
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Replaces each substring of this string that matches the given regular expression with the
given replacement.
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Replaces the first substring of this string that matches the given regular expression with the
given replacement.
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Resolves this instance as a ConstantDesc, the result of which is
the instance itself.
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String[] |
Splits this string around matches of the given regular expression.
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String[] |
Splits this string around matches of the given
regular expression.
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boolean |
startsWith(String prefix)
Tests if this string starts with the specified prefix.
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boolean |
startsWith(String prefix, int toffset)
Tests if the substring of this string beginning at the
specified index starts with the specified prefix.
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strip()
Returns a string whose value is this string, with all leading
and trailing white space
removed.
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Returns a string whose value is this string, with incidental
white space removed from
the beginning and end of every line.
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Returns a string whose value is this string, with all leading
white space removed.
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Returns a string whose value is this string, with all trailing
white space removed.
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subSequence(int beginIndex, int endIndex)
Returns a character sequence that is a subsequence of this sequence.
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substring(int beginIndex)
Returns a string that is a substring of this string.
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substring(int beginIndex, int endIndex)
Returns a string that is a substring of this string.
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char[] |
Converts this string to a new character array.
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Converts all of the characters in this String to lower
case using the rules of the default locale.
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toLowerCase(Locale locale)
Converts all of the characters in this String to lower
case using the rules of the given Locale.
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toString()
This object (which is already a string!) is itself returned.
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Converts all of the characters in this String to upper
case using the rules of the default locale.
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toUpperCase(Locale locale)
Converts all of the characters in this String to upper
case using the rules of the given Locale.
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This method allows the application of a function to this
string.
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Returns a string whose value is this string, with escape sequences
translated as if in a string literal.
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trim()
Returns a string whose value is this string, with all leading
and trailing space removed, where space is defined
as any character whose codepoint is less than or equal to
'U+0020' (the space character).
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static String |
valueOf(boolean b)
Returns the string representation of the boolean argument.
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static String |
valueOf(char c)
Returns the string representation of the char
argument.
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static String |
valueOf(char[] data)
Returns the string representation of the char array
argument.
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static String |
valueOf(char[] data, int offset, int count)
Returns the string representation of a specific subarray of the
char array argument.
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static String |
valueOf(double d)
Returns the string representation of the double argument.
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static String |
valueOf(float f)
Returns the string representation of the float argument.
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static String |
valueOf(int i)
Returns the string representation of the int argument.
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static String |
valueOf(long l)
Returns the string representation of the long argument.
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static String |
Returns the string representation of the Object argument.
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Methods inherited from class java.lang.Object |
Methods inherited from interface java.lang.CharSequence |
Note that this Comparator does not take locale into account, and will result in an unsatisfactory ordering for certain locales. The Collator class provides locale-sensitive comparison.
public String |
() |
public String |
(String original) |
public String |
(char[] value) |
public String |
(char[] value, int offset, int count) |
public String |
(int[] codePoints, int offset, int count) |
public String |
(byte[] ascii, int hibyte, int offset, int count) |
The offset argument is the index of the first byte of the subarray, and the count argument specifies the length of the subarray.
Each byte in the subarray is converted to a char as specified in the String(byte[],int) constructor.
public String |
(byte[] ascii, int hibyte) |
c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
public String |
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throws |
The behavior of this constructor when the given bytes are not valid in the given charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement string. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
(byte[] bytes, String charsetName) |
throws |
The behavior of this constructor when the given bytes are not valid in the given charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
(byte[] bytes, Charset charset) |
This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement string. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
(byte[] bytes, int offset, int length) |
The behavior of this constructor when the given bytes are not valid in the default charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
(byte[] bytes) |
The behavior of this constructor when the given bytes are not valid in the default charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.
public String |
(StringBuffer buffer) |
public String |
(StringBuilder builder) |
This constructor is provided to ease migration to StringBuilder. Obtaining a string from a string builder via the toString method is likely to run faster and is generally preferred.
public int length |
() |
public boolean isEmpty |
() |
public char charAt |
(int index) |
If the char value specified by the index is a surrogate, the surrogate value is returned.
public int codePointAt |
(int index) |
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.
public int codePointBefore |
(int index) |
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.
public int codePointCount |
(int beginIndex, int endIndex) |
public int offsetByCodePoints |
(int index, int codePointOffset) |
public void getChars |
(int srcBegin, int srcEnd, char[] dst, int dstBegin) |
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
public void getBytes |
(int srcBegin, int srcEnd, byte[] dst, int dstBegin) |
The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1. The total number of characters to be copied is srcEnd-srcBegin. The characters, converted to bytes, are copied into the subarray of dst starting at index dstBegin and ending at index:
dstBegin + (srcEnd-srcBegin) - 1
public byte[] getBytes |
(String charsetName) |
throws |
The behavior of this method when this string cannot be encoded in the given charset is unspecified. The CharsetEncoder class should be used when more control over the encoding process is required.
public byte[] getBytes |
(Charset charset) |
This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement byte array. The CharsetEncoder class should be used when more control over the encoding process is required.
public byte[] getBytes |
() |
The behavior of this method when this string cannot be encoded in the default charset is unspecified. The CharsetEncoder class should be used when more control over the encoding process is required.
public boolean equals |
(Object anObject) |
For finer-grained String comparison, refer to Collator.
public boolean contentEquals |
(StringBuffer sb) |
For finer-grained String comparison, refer to Collator.
public boolean contentEquals |
(CharSequence cs) |
For finer-grained String comparison, refer to Collator.
public boolean equalsIgnoreCase |
(String anotherString) |
Two Unicode code points are considered the same ignoring case if at least one of the following is true:
Note that this method does not take locale into account, and will result in unsatisfactory results for certain locales. The Collator class provides locale-sensitive comparison.
public int compareTo |
(String anotherString) |
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:
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.charAt(k)-anotherString.charAt(k)
this.length()-anotherString.length()
For finer-grained String comparison, refer to Collator.
public int compareToIgnoreCase |
(String str) |
Note that this method does not take locale into account, and will result in an unsatisfactory ordering for certain locales. The Collator class provides locale-sensitive comparison.
public boolean regionMatches |
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:
Note that this method does not take locale into account. The Collator class provides locale-sensitive comparison.
public boolean regionMatches |
A substring of this String object is compared to a substring of the argument other. The result is true if these substrings represent Unicode code point sequences that are the same, ignoring case if and only if ignoreCase is true. The sequences tsequence and osequence are compared, where tsequence is the sequence produced as if by calling this.substring(toffset, toffset + len).codePoints() and osequence is the sequence produced as if by calling other.substring(ooffset, ooffset + len).codePoints(). The result is true if and only if all of the following are true:
Note that this method does not take locale into account, and will result in unsatisfactory results for certain locales when ignoreCase is true. The Collator class provides locale-sensitive comparison.
public boolean startsWith |
(String prefix, int toffset) |
this.substring(toffset).startsWith(prefix)
public boolean startsWith |
(String prefix) |
public boolean endsWith |
(String suffix) |
public int hashCode |
() |
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.)s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
public int indexOf |
(int ch) |
is true. For other values of ch, it is the smallest value k such that:this.charAt(k) == ch
is true. In either case, if no such character occurs in this string, then -1 is returned.this.codePointAt(k) == ch
public int indexOf |
(int ch, int fromIndex) |
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).
public int lastIndexOf |
(int ch) |
is true. For other values of ch, it is the largest value k such that:this.charAt(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.this.codePointAt(k) == ch
public int lastIndexOf |
(int ch, int fromIndex) |
(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).
public int indexOf |
(String str) |
The returned index is the smallest value k for which:
this.startsWith(str, k)
If no such value of k exists, then -1 is returned.
public int indexOf |
(String str, int fromIndex) |
The returned index 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.
public int lastIndexOf |
(String str) |
The returned index is the largest value k for which:
this.startsWith(str, k)
If no such value of k exists, then -1 is returned.
public int lastIndexOf |
(String str, int fromIndex) |
The returned index is the largest 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.
public String substring |
(int beginIndex) |
Examples:
"unhappy".substring(2) returns "happy" "Harbison".substring(3) returns "bison" "emptiness".substring(9) returns "" (an empty string)
public String substring |
(int beginIndex, int endIndex) |
Examples:
"hamburger".substring(4, 8) returns "urge" "smiles".substring(1, 5) returns "mile"
public CharSequence subSequence |
(int beginIndex, int endIndex) |
An invocation of this method of the form
behaves in exactly the same way as the invocationstr.subSequence(begin, end)
str.substring(begin, end)
public String concat |
(String str) |
If the length of the argument string is 0, then this String object is returned. Otherwise, a String object is returned that represents 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"
public String replace |
(char oldChar, char 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 String object is returned 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)
public boolean matches |
(String regex) |
An invocation of this method of the form str.matches(regex) yields exactly the same result as the expression
Pattern.matches(regex, str)
public boolean contains |
(CharSequence s) |
public String replaceFirst |
An invocation of this method of the form str.replaceFirst(regex, repl) yields exactly the same result as the expression
Pattern.compile(regex).matcher(str).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 Matcher.replaceFirst(String). Use Matcher.quoteReplacement(String) to suppress the special meaning of these characters, if desired.
public String replaceAll |
An invocation of this method of the form str.replaceAll(regex, repl) yields exactly the same result as the expression
Pattern.compile(regex).matcher(str).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 Matcher.replaceAll. Use Matcher.quoteReplacement(String) to suppress the special meaning of these characters, if desired.
public String replace |
public String[] split |
(String regex, int limit) |
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.
When there is a positive-width match at the beginning of this string then an empty leading substring is included at the beginning of the resulting array. A zero-width match at the beginning however never produces such empty leading substring.
The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array.
If the limit is positive then the pattern will be applied at most limit - 1 times, the array's length will be no greater than limit, and the array's last entry will contain all input beyond the last matched delimiter.
If the limit 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.
If the limit is negative then the pattern will be applied as many times as possible and the array can have any length.
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", "", "" } -2 { "b", "", ":and:f", "", "" } 0 { "b", "", ":and:f" }
An invocation of this method of the form str.split(regex, n) yields the same result as the expression
Pattern.compile(regex).split(str, n)
public String[] split |
(String regex) |
This method works as if by invoking the two-argument 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" }
public static String join |
For example,
String message = String.join("-", "Java", "is", "cool");
// message returned is: "Java-is-cool"
Note that if an element is null, then "null" is added.
public static String join |
For example,
List<String> strings = List.of("Java", "is", "cool");
String message = String.join(" ", strings);
// message returned is: "Java is cool"
Set<String> strings =
new LinkedHashSet<>(List.of("Java", "is", "very", "cool"));
String message = String.join("-", strings);
// message returned is: "Java-is-very-cool"
Note that if an individual element is null, then "null" is added.
public String toLowerCase |
(Locale locale) |
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) | ΙΧΘΥΣ | ιχθυσ | lowercased all chars in String |
public String toLowerCase |
() |
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.ROOT).
public String toUpperCase |
(Locale locale) |
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 |
public String toUpperCase |
() |
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.ROOT).
public String trim |
() |
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 that are not space (as defined above), then a reference to this String object is returned.
Otherwise, if all characters in this string are space (as defined above), then a String object representing an empty string is returned.
Otherwise, let k be the index of the first character in the string whose code is not a space (as defined above) and let m be the index of the last character in the string whose code is not a space (as defined above). A String object is returned, 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 space (as defined above) from the beginning and end of a string.
public String strip |
() |
If this String object represents an empty string, or if all code points in this string are white space, then an empty string is returned.
Otherwise, returns a substring of this string beginning with the first code point that is not a white space up to and including the last code point that is not a white space.
This method may be used to strip white space from the beginning and end of a string.
public String stripLeading |
() |
If this String object represents an empty string, or if all code points in this string are white space, then an empty string is returned.
Otherwise, returns a substring of this string beginning with the first code point that is not a white space up to and including the last code point of this string.
This method may be used to trim white space from the beginning of a string.
public String stripTrailing |
() |
If this String object represents an empty string, or if all characters in this string are white space, then an empty string is returned.
Otherwise, returns a substring of this string beginning with the first code point of this string up to and including the last code point that is not a white space.
This method may be used to trim white space from the end of a string.
public boolean isBlank |
() |
() |
A line terminator is one of the following: a line feed character "\n" (U+000A), a carriage return character "\r" (U+000D), or a carriage return followed immediately by a line feed "\r\n" (U+000D U+000A).
A line is either a sequence of zero or more characters followed by a line terminator, or it is a sequence of one or more characters followed by the end of the string. A line does not include the line terminator.
The stream returned by this method contains the lines from this string in the order in which they occur.
public String indent |
(int n) |
This string is conceptually separated into lines using lines(). Each line is then adjusted as described below and then suffixed with a line feed "\n" (U+000A). The resulting lines are then concatenated and returned.
If n > 0 then n spaces (U+0020) are inserted at the beginning of each line.
If n < 0 then up to n white space characters are removed from the beginning of each line. If a given line does not contain sufficient white space then all leading white space characters are removed. Each white space character is treated as a single character. In particular, the tab character "\t" (U+0009) is considered a single character; it is not expanded.
If n == 0 then the line remains unchanged. However, line terminators are still normalized.
public String stripIndent |
() |
Incidental white space is often present in a text block to align the content with the opening delimiter. For example, in the following code, dots represent incidental white space:
This method treats the incidental white space as indentation to be stripped, producing a string that preserves the relative indentation of the content. Using | to visualize the start of each line of the string:String html = """ ..............<html> .............. <body> .............. <p>Hello, world</p> .............. </body> ..............</html> ..............""";
First, the individual lines of this string are extracted. A line is a sequence of zero or more characters followed by either a line terminator or the end of the string. If the string has at least one line terminator, the last line consists of the characters between the last terminator and the end of the string. Otherwise, if the string has no terminators, the last line is the start of the string to the end of the string, in other words, the entire string. A line does not include the line terminator.|<html> | <body> | <p>Hello, world</p> | </body> |</html>
Then, the minimum indentation (min) is determined as follows:
For each non-blank line (as defined by isBlank()), the leading white space characters are counted.
The leading white space characters on the last line are also counted even if blank.
The min value is the smallest of these counts.
For each non-blank line, min leading white space characters are removed, and any trailing white space characters are removed. Blank lines are replaced with the empty string.
Finally, the lines are joined into a new string, using the LF character "\n" (U+000A) to separate lines.
public String translateEscapes |
() |
Escape sequences are translated as follows;
Escape | Name | Translation |
---|---|---|
\b | backspace | U+0008 |
\t | horizontal tab | U+0009 |
\n | line feed | U+000A |
\f | form feed | U+000C |
\r | carriage return | U+000D |
\s | space | U+0020 |
\" | double quote | U+0022 |
\' | single quote | U+0027 |
\\ | backslash | U+005C |
\0 - \377 | octal escape | code point equivalents |
\<line-terminator> | continuation | discard |
Any exception thrown by f.apply() will be propagated to the caller.
public String toString |
() |
public IntStream chars |
() |
public IntStream codePoints |
() |
public char[] toCharArray |
() |
public static String format |
The locale always used is the one returned by Locale.getDefault(Locale.Category) with FORMAT category specified.
public static String format |
public String formatted |
(Object... args) |
public static String valueOf |
(Object obj) |
public static String valueOf |
(char[] data) |
public static String valueOf |
(char[] data, int offset, int count) |
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 returned string.
public static String copyValueOf |
(char[] data, int offset, int count) |
public static String copyValueOf |
(char[] data) |
public static String valueOf |
(boolean b) |
public static String valueOf |
(char c) |
public static String valueOf |
(int i) |
The representation is exactly the one returned by the Integer.toString method of one argument.
public static String valueOf |
(long l) |
The representation is exactly the one returned by the Long.toString method of one argument.
public static String valueOf |
(float f) |
The representation is exactly the one returned by the Float.toString method of one argument.
public static String valueOf |
(double d) |
The representation is exactly the one returned by the Double.toString method of one argument.
public String intern |
() |
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 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 section {@jls 3.10.5} of the The Java Language Specification.
public String repeat |
(int count) |
If this string is empty or count is zero then the empty string is returned.
() |
public String resolveConstantDesc |
(MethodHandles.Lookup lookup) |
|
FlexDoc/Javadoc 2.0 Demo Java Doc |