String

java.lang.Object
- java.lang.String

All Implemented Interfaces:

CharSequence, Comparable<String>
```
public final class String
extends Object
implements CharSequence, Comparable<String>
```
An immutable string of characters.

Constructor Summary

Constructors
Constructor and Description
`String()`
`String(byte[] b)` Create a String from a byte array
`String(byte[] b, int off, int len)` Create a String from a byte array
`String(byte[] b, int off, int len, String charset)` Create a String from a byte array
`String(byte[] b, String charset)` Create a String from a byte array
`String(char[] c)` Create a String from a character array
`String(char[] c, int off, int len)` Create a String from a character array.
`String(int[] codePoints, int off, int len)`
`String(String s)`
`String(StringBuffer sb)`
`String(StringBuilder sb)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`char`	`charAt(int index)` Return the character at the given index
`int`	`codePointAt(int index)`
`int`	`codePointBefore(int index)`
`int`	`codePointCount(int begin, int end)`
`int`	`compareTo(String str)` Compares this with another Object.
`int`	`compareToIgnoreCase(String str)` Compares this String and another String (case insensitive).
`String`	`concat(String s)`
`boolean`	`contains(CharSequence s)` Returns true iff this String contains the sequence of Characters described in s.
`boolean`	`contentEquals(CharSequence s)`
`boolean`	`contentEquals(StringBuffer sb)`
`static String`	`copyValueOf(char[] data)`
`static String`	`copyValueOf(char[] data, int off, int len)`
`boolean`	`endsWith(String suffix)` Predicate which determines if this String ends with a given suffix.
`boolean`	`equals(Object other)` Compares the String with an Object
`boolean`	`equalsIgnoreCase(String s)`
`static String`	`format(String format, Object... args)`
`byte[]`	`getBytes()`
`void`	`getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin)`
`byte[]`	`getBytes(String charset)` Get bytes in US Acsii
`void`	`getChars(int start, int end, char[] buffer, int off)`
`int`	`hashCode()` Special version of hash that returns the same value the same String values
`int`	`indexOf(int ch)` Find the index of a character.
`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.
`int`	`indexOf(String str)` Finds the location of a string within this string
`int`	`indexOf(String str, int fromIndex)` Find location of String starting at a given index
`String`	`intern()`
`boolean`	`isEmpty()` Returns true, if and only if this string is of zero length.
`int`	`lastIndexOf(int ch)`
`int`	`lastIndexOf(int ch, int fromIndex)`
`int`	`lastIndexOf(String str)` Find the last occurrence of a String
`int`	`lastIndexOf(String str, int fromIndex)` Find last occurrence of s string from a given index
`int`	`length()` Return the length of the String in characters
`int`	`offsetByCodePoints(int idx, int codePointCount)`
`boolean`	`regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)` Tests if two string regions are equal.
`boolean`	`regionMatches(int toffset, String other, int ooffset, int len)` Tests if two string regions are equal.
`String`	`replace(char oldChar, char newChar)`
`String[]`	`split(String seperators)` Split this string around the matches of a character string.
`boolean`	`startsWith(String s)` Predicate which determines if this String starts with a given prefix.
`boolean`	`startsWith(String s, int begin)`
`CharSequence`	`subSequence(int start, int end)` Returns a new `CharSequence` of the indicated range.
`String`	`substring(int start)` Return substring from starting position to the end of the String
`String`	`substring(int start, int end)` Return substring from starting index to position before end index
`char[]`	`toCharArray()` Converts the String into an array of characters
`String`	`toLowerCase()`
`String`	`toString()` Returns itself.
`String`	`toUpperCase()`
`String`	`trim()`
`static String`	`valueOf(boolean b)`
`static String`	`valueOf(char c)`
`static String`	`valueOf(char[] c)`
`static String`	`valueOf(char[] c, int start, int length)`
`static String`	`valueOf(double d)`
`static String`	`valueOf(float f)`
`static String`	`valueOf(int i)`
`static String`	`valueOf(long i)`
`static String`	`valueOf(Object aObj)` Converts an Object to a String

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - String
```
public String()
```
  - String
```
public String(byte[] b)
```
    Create a String from a byte array
    
    Parameters:
    
    b - the byte array
  - String
```
public String(byte[] b,
              int off,
              int len)
```
    Create a String from a byte array
    
    Parameters:
    
    b - the byte array
  - String
```
public String(byte[] b,
              int off,
              int len,
              String charset)
```
    Create a String from a byte array
    
    Parameters:
    
    b - the byte array
    
    charset - ignored - assumed to be US ASCII
  - String
```
public String(byte[] b,
              String charset)
```
    Create a String from a byte array
    
    Parameters:
    
    b - the byte array
    
    charset - ignored - assumed to be US ASCII
  - String
```
public String(char[] c)
```
    Create a String from a character array
    
    Parameters:
    
    c - the character array
  - String
```
public String(char[] c,
              int off,
              int len)
```
    Create a String from a character array.
    
    Parameters:
    
    c - the character array
    
    off - the offset - usually 0
    
    len - the length of the String - must not be greater than c.length
  - String
```
public String(int[] codePoints,
              int off,
              int len)
```
  - String
```
public String(String s)
```
  - String
```
public String(StringBuffer sb)
```
  - String
```
public String(StringBuilder sb)
```
- Method Detail
  - charAt
```
public char charAt(int index)
```
    Return the character at the given index
    
    Specified by:
    
    charAt in interface CharSequence
    
    Parameters:
    
    index - the index to retrieve from
    
    Returns:
    
    the characters at the given index
  - codePointAt
```
public int codePointAt(int index)
```
  - codePointBefore
```
public int codePointBefore(int index)
```
  - codePointCount
```
public int codePointCount(int begin,
                          int end)
```
  - compareTo
```
public int compareTo(String str)
```
    Description copied from interface: Comparable
    
    Compares this with another Object. Returns -1 if this object is smaller, 0 if both objects are equal and 1 if this object is bigger.
    
    Specified by:
    
    compareTo in interface Comparable<String>
    
    Parameters:
    
    str - the object to compare with
    
    Returns:
    
    one of the values -1, 0, 1
  - compareToIgnoreCase
```
public int compareToIgnoreCase(String str)
```
    Compares this String and another String (case insensitive). This comparison is similar to equalsIgnoreCase
    
    Parameters:
    
    str - the string to compare against
    
    Returns:
    
    the comparison
    
    Since:
    
    1.2
  - concat
```
public String concat(String s)
```
  - contains
```
public boolean contains(CharSequence s)
```
    Returns true iff this String contains the sequence of Characters described in s.
    
    Parameters:
    
    s - the CharSequence
    
    Returns:
    
    true iff this String contains s
    
    Since:
    
    1.5
  - contentEquals
```
public boolean contentEquals(CharSequence s)
```
  - contentEquals
```
public boolean contentEquals(StringBuffer sb)
```
  - copyValueOf
```
public static String copyValueOf(char[] data)
```
  - copyValueOf
```
public static String copyValueOf(char[] data,
                                 int off,
                                 int len)
```
  - endsWith
```
public boolean endsWith(String suffix)
```
    Predicate which determines if this String ends with a given suffix. If the suffix is an empty String, true is returned.
    
    Parameters:
    
    suffix - String to compare
    
    Returns:
    
    true if this String ends with the suffix
    
    Throws:
    
    NullPointerException - if suffix is null
  - equals
```
public boolean equals(Object other)
```
    Compares the String with an Object
    
    Overrides:
    
    equals in class Object
    
    Returns:
    
    true if the String is equal to the object, false otherwise
  - equalsIgnoreCase
```
public boolean equalsIgnoreCase(String s)
```
  - format
```
public static String format(String format,
                            Object... args)
```
    Since:
    
    1.5
  - getBytes
```
public byte[] getBytes()
```
  - getBytes
```
public void getBytes(int srcBegin,
                     int srcEnd,
                     byte[] dst,
                     int dstBegin)
```
  - getBytes
```
public byte[] getBytes(String charset)
```
    Get bytes in US Acsii
    
    Parameters:
    
    charset - ignored
    
    Returns:
    
    the ascii bytes
  - getChars
```
public void getChars(int start,
                     int end,
                     char[] buffer,
                     int off)
```
  - hashCode
```
public int hashCode()
```
    Special version of hash that returns the same value the same String values
    
    Overrides:
    
    hashCode in class Object
  - indexOf
```
public int indexOf(int ch)
```
    Find the index of a character.
    
    Parameters:
    
    ch - The character to find.
    
    Returns:
    
    The index of the character. -1 means it wasn't found.
  - indexOf
```
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.
    
    Parameters:
    
    ch - a character (Unicode code point).
    
    fromIndex - the index to start the search from.
    
    Returns:
    
    the index of the first occurrence of the character in the character sequence represented by this object that is greater than or equal to fromIndex, or -1 if the character does not occur.
  - indexOf
```
public int indexOf(String str)
```
    Finds the location of a string within this string
    
    Parameters:
    
    str - the String
    
    Returns:
    
    Index of string location, -1 if string does not exist.
  - indexOf
```
public int indexOf(String str,
                   int fromIndex)
```
    Find location of String starting at a given index
    
    Parameters:
    
    str - the String
    
    fromIndex - the starting position
    
    Returns:
    
    Index of string location, -1 if string does not exist.
  - intern
```
public String intern()
```
  - isEmpty
```
public boolean isEmpty()
```
    Returns true, if and only if this string is of zero length.
    
    Returns:
    
    true if this string is of zero length, false otherwise.
  - lastIndexOf
```
public int lastIndexOf(int ch)
```
  - lastIndexOf
```
public int lastIndexOf(int ch,
                       int fromIndex)
```
  - lastIndexOf
```
public int lastIndexOf(String str)
```
    Find the last occurrence of a String
    
    Parameters:
    
    str - the String
    
    Returns:
    
    index of string location, -1 if string does not exist.
  - lastIndexOf
```
public int lastIndexOf(String str,
                       int fromIndex)
```
    Find last occurrence of s string from a given index
    
    Parameters:
    
    str - the String
    
    fromIndex - the starting point
    
    Returns:
    
    index of string location, -1 if string does not exist.
  - length
```
public int length()
```
    Return the length of the String in characters
    
    Specified by:
    
    length in interface CharSequence
    
    Returns:
    
    the length of the String
  - offsetByCodePoints
```
public int offsetByCodePoints(int idx,
                              int codePointCount)
```
  - regionMatches
```
public boolean regionMatches(boolean ignoreCase,
                             int toffset,
                             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))
    Parameters:
    
    ignoreCase - if true, ignore case when comparing characters.
    
    toffset - the starting offset of the subregion in this string.
    
    other - the string argument.
    
    ooffset - the starting offset of the subregion in the string argument.
    
    len - the number of characters to compare.
    
    Returns:
    
    true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise. Whether the matching is exact or case insensitive depends on the ignoreCase argument.
  - regionMatches
```
public boolean regionMatches(int toffset,
                             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)
    Parameters:
    
    toffset - the starting offset of the subregion in this string.
    
    other - the string argument.
    
    ooffset - the starting offset of the subregion in the string argument.
    
    len - the number of characters to compare.
    
    Returns:
    
    true if the specified subregion of this string exactly matches the specified subregion of the string argument; false otherwise.
  - replace
```
public String replace(char oldChar,
                      char newChar)
```
  - split
```
public String[] split(String seperators)
```
    Split this string around the matches of a character string.
    
    Parameters:
    
    seperators - string to match
    
    Returns:
    
    the array of split strings
    
    Since:
    
    1.4
  - startsWith
```
public boolean startsWith(String s)
```
    Predicate which determines if this String starts with a given prefix. If the prefix is an empty String, true is returned.
    
    Returns:
    
    true if this String starts with the prefix
    
    Throws:
    
    NullPointerException - if prefix is null
    
    See Also:
    
    startsWith(String, int)
  - startsWith
```
public boolean startsWith(String s,
                          int begin)
```
  - subSequence
```
public CharSequence subSequence(int start,
                                int end)
```
    Description copied from interface: CharSequence
    
    Returns a new CharSequence of the indicated range.
    
    Specified by:
    
    subSequence in interface CharSequence
    
    Parameters:
    
    start - the start index (inclusive)
    
    end - the end index (exclusive)
    
    Returns:
    
    a subsequence of this
  - substring
```
public String substring(int start)
```
    Return substring from starting position to the end of the String
    
    Parameters:
    
    start - the starting position
    
    Returns:
    
    the substring
  - substring
```
public String substring(int start,
                        int end)
```
    Return substring from starting index to position before end index
    
    Parameters:
    
    start - the start index
    
    end - the end index (not included)
    
    Returns:
    
    the substring
  - toCharArray
```
public char[] toCharArray()
```
    Converts the String into an array of characters
    
    Returns:
    
    the character Array
  - toLowerCase
```
public String toLowerCase()
```
  - toString
```
public String toString()
```
    Returns itself.
    
    Specified by:
    
    toString in interface CharSequence
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    the String itself
  - toUpperCase
```
public String toUpperCase()
```
  - trim
```
public String trim()
```
  - valueOf
```
public static String valueOf(boolean b)
```
  - valueOf
```
public static String valueOf(char c)
```
  - valueOf
```
public static String valueOf(char[] c)
```
  - valueOf
```
public static String valueOf(char[] c,
                             int start,
                             int length)
```
  - valueOf
```
public static String valueOf(double d)
```
  - valueOf
```
public static String valueOf(float f)
```
  - valueOf
```
public static String valueOf(int i)
```
  - valueOf
```
public static String valueOf(long i)
```
  - valueOf
```
public static String valueOf(Object aObj)
```
    Converts an Object to a String
    
    Returns:
    
    the String that represents the object

Class String

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

String

String

String

String

String

String

String

String

String

String

String

Method Detail

charAt

codePointAt

codePointBefore

codePointCount

compareTo

compareToIgnoreCase

concat

contains

contentEquals

contentEquals

copyValueOf

copyValueOf

endsWith

equals

equalsIgnoreCase

format

getBytes

getBytes

getBytes

getChars

hashCode

indexOf

indexOf

indexOf

indexOf

intern

isEmpty

lastIndexOf

lastIndexOf

lastIndexOf

lastIndexOf

length

offsetByCodePoints

regionMatches

regionMatches

replace

split

startsWith

startsWith

subSequence

substring

substring

toCharArray

toLowerCase

toString

toUpperCase

trim

valueOf

valueOf

valueOf

valueOf

valueOf

valueOf

valueOf

valueOf

valueOf