StringBuilder

java.lang.Object
- java.lang.StringBuilder

All Implemented Interfaces:

Appendable, CharSequence
```
public class StringBuilder
extends Object
implements CharSequence, Appendable
```
An expandable string of characters. Actually not very expandable! 09/25/2001 added number formatting thanks to Martin E. Nielsen. You must ensure that the buffer is large enough to take the formatted number.

Author:

Martin E. Nielsen, Sven Köhler

Constructor Summary

Constructors
Constructor and Description

StringBuilder()

StringBuilder(CharSequence seq)

StringBuilder(int length)

StringBuilder(String aString)

Constructors
Constructor and Description
`StringBuilder()`
`StringBuilder(CharSequence seq)`
`StringBuilder(int length)`
`StringBuilder(String aString)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`StringBuilder`	`append(boolean aBoolean)`
`StringBuilder`	`append(char aChar)` Appends the Unicode character, c, to this `Appendable` object.
`StringBuilder`	`append(char[] c)`
`StringBuilder`	`append(char[] c, int off, int len)`
`StringBuilder`	`append(CharSequence cs)` Appends the specified sequence of Unicode characters to this `Appendable` object.
`StringBuilder`	`append(CharSequence cs, int start, int end)` Appends the specified subsequence of Unicode characters to this `Appendable` object, starting and ending at the specified positions within the sequence.
`StringBuilder`	`append(double aDouble)`
`StringBuilder`	`append(float aFloat)`
`StringBuilder`	`append(int i)`
`StringBuilder`	`append(long aLong)`
`StringBuilder`	`append(Object aObject)`
`StringBuilder`	`append(String s)`
`StringBuilder`	`append(StringBuffer sb)`
`StringBuilder`	`appendCodePoint(int cp)`
`int`	`capacity()`
`char`	`charAt(int i)` Returns the character at the given index.
`StringBuilder`	`delete(int start, int end)`
`StringBuilder`	`deleteCharAt(int index)`
`void`	`ensureCapacity(int minCapacity)`
`void`	`getChars(int start, int end, char[] dst, int dstStart)` Retrieves the contents of the StringBuilder in the form of an array of characters.
`int`	`indexOf(String str)`
`int`	`indexOf(String str, int fromIndex)`
`StringBuilder`	`insert(int offset, char[] data)` Insert the `char[]` argument into this `StringBuffer`.
`StringBuilder`	`insert(int offset, char[] str, int str_offset, int len)` Insert a subarray of the `char[]` argument into this `StringBuffer`.
`StringBuilder`	`insert(int offset, Object obj)` Insert the `String` value of the argument into this `StringBuffer`.
`StringBuilder`	`insert(int offset, String str)` Insert the `String` argument into this `StringBuffer`.
`int`	`lastIndexOf(String str)`
`int`	`lastIndexOf(String str, int fromIndex)`
`int`	`length()` Returns the length of the sequence.
`StringBuilder`	`replace(int start, int end, String str)` Replace characters between index `start` (inclusive) and `end` (exclusive) with `str`.
`StringBuilder`	`reverse()` Reverse the characters in this StringBuffer.
`void`	`setCharAt(int i, char ch)`
`void`	`setLength(int newLen)`
`CharSequence`	`subSequence(int start, int end)` Returns a new `CharSequence` of the indicated range.
`String`	`substring(int start)`
`String`	`substring(int start, int end)`
`String`	`toString()` Returns the complete `CharSequence` as a `String`.
`void`	`trimToSize()`

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

- Constructor Detail
  - StringBuilder
```
public StringBuilder()
```
  - StringBuilder
```
public StringBuilder(CharSequence seq)
```
  - StringBuilder
```
public StringBuilder(int length)
```
  - StringBuilder
```
public StringBuilder(String aString)
```
- Method Detail
  - append
```
public StringBuilder append(boolean aBoolean)
```
  - append
```
public StringBuilder append(char aChar)
```
    Description copied from interface: Appendable
    
    Appends the Unicode character, c, to this Appendable object.
    
    Specified by:
    
    append in interface Appendable
    
    Parameters:
    
    aChar - the character to append.
    
    Returns:
    
    a reference to this object.
  - append
```
public StringBuilder append(char[] c)
```
  - append
```
public StringBuilder append(char[] c,
                            int off,
                            int len)
```
  - append
```
public StringBuilder append(CharSequence cs)
```
    Description copied from interface: Appendable
    
    Appends the specified sequence of Unicode characters to this Appendable object. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended.
    
    Specified by:
    
    append in interface Appendable
    
    Parameters:
    
    cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.
    
    Returns:
    
    a reference to this object.
  - append
```
public StringBuilder append(CharSequence cs,
                            int start,
                            int end)
```
    Description copied from interface: Appendable
    
    Appends the specified subsequence of Unicode characters to this Appendable object, starting and ending at the specified positions within the sequence. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended. The behaviour of this method matches the behaviour of append(seq.subSequence(start,end)) when the sequence is not null.
    
    Specified by:
    
    append in interface Appendable
    
    Parameters:
    
    cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.
    
    start - the index of the first Unicode character to use from the sequence.
    
    end - the index of the last Unicode character to use from the sequence.
    
    Returns:
    
    a reference to this object.
  - append
```
public StringBuilder append(double aDouble)
```
  - append
```
public StringBuilder append(float aFloat)
```
  - append
```
public StringBuilder append(int i)
```
  - append
```
public StringBuilder append(long aLong)
```
  - append
```
public StringBuilder append(Object aObject)
```
  - append
```
public StringBuilder append(String s)
```
  - append
```
public StringBuilder append(StringBuffer sb)
```
  - appendCodePoint
```
public StringBuilder appendCodePoint(int cp)
```
  - capacity
```
public int capacity()
```
  - charAt
```
public char charAt(int i)
```
    Description copied from interface: CharSequence
    
    Returns the character at the given index.
    
    Specified by:
    
    charAt in interface CharSequence
    
    Parameters:
    
    i - the index to retrieve from
    
    Returns:
    
    the character at that location
  - delete
```
public StringBuilder delete(int start,
                            int end)
```
  - deleteCharAt
```
public StringBuilder deleteCharAt(int index)
```
  - ensureCapacity
```
public void ensureCapacity(int minCapacity)
```
  - getChars
```
public void getChars(int start,
                     int end,
                     char[] dst,
                     int dstStart)
```
    Retrieves the contents of the StringBuilder in the form of an array of characters.
  - indexOf
```
public int indexOf(String str)
```
  - indexOf
```
public int indexOf(String str,
                   int fromIndex)
```
  - insert
```
public StringBuilder insert(int offset,
                            char[] data)
```
    Insert the char[] argument into this StringBuffer.
    
    Parameters:
    
    offset - the place to insert in this buffer
    
    data - the char[] to insert
    
    Returns:
    
    this StringBuffer
    
    Throws:
    
    NullPointerException - if data is null
    
    StringIndexOutOfBoundsException - if offset is out of bounds
    
    See Also:
    
    insert(int, char[], int, int)
  - insert
```
public StringBuilder insert(int offset,
                            char[] str,
                            int str_offset,
                            int len)
```
    Insert a subarray of the char[] argument into this StringBuffer.
    
    Parameters:
    
    offset - the place to insert in this buffer
    
    str - the char[] to insert
    
    str_offset - the index in str to start inserting from
    
    len - the number of characters to insert
    
    Returns:
    
    this StringBuffer
    
    Throws:
    
    NullPointerException - if str is null
    
    StringIndexOutOfBoundsException - if any index is out of bounds
    
    Since:
    
    1.2
  - insert
```
public StringBuilder insert(int offset,
                            Object obj)
```
    Insert the String value of the argument into this StringBuffer. Uses String.valueOf() to convert to String.
    
    Parameters:
    
    offset - the place to insert in this buffer
    
    obj - the Object to convert and insert
    
    Returns:
    
    this StringBuffer
    
    Throws:
    
    StringIndexOutOfBoundsException - if offset is out of bounds
    
    See Also:
    
    String.valueOf(Object)
  - insert
```
public StringBuilder insert(int offset,
                            String str)
```
    Insert the String argument into this StringBuffer. If str is null, the String "null" is used instead.
    
    Parameters:
    
    offset - the place to insert in this buffer
    
    str - the String to insert
    
    Returns:
    
    this StringBuffer
    
    Throws:
    
    StringIndexOutOfBoundsException - if offset is out of bounds
  - lastIndexOf
```
public int lastIndexOf(String str)
```
  - lastIndexOf
```
public int lastIndexOf(String str,
                       int fromIndex)
```
  - length
```
public int length()
```
    Description copied from interface: CharSequence
    
    Returns the length of the sequence. This is the number of 16-bit characters in the sequence, which may differ from the length of the underlying encoding.
    
    Specified by:
    
    length in interface CharSequence
    
    Returns:
    
    the sequence length
  - replace
```
public StringBuilder replace(int start,
                             int end,
                             String str)
```
    Replace characters between index start (inclusive) and end (exclusive) with str. If end is larger than the size of this StringBuffer, all characters after start are replaced.
    
    Parameters:
    
    start - the beginning index of characters to delete (inclusive)
    
    end - the ending index of characters to delete (exclusive)
    
    str - the new String to insert
    
    Returns:
    
    this StringBuffer
    
    Throws:
    
    StringIndexOutOfBoundsException - if start or end are out of bounds
    
    NullPointerException - if str is null
    
    Since:
    
    1.2
  - reverse
```
public StringBuilder reverse()
```
    Reverse the characters in this StringBuffer. The same sequence of characters exists, but in the reverse index ordering.
    
    Returns:
    
    this StringBuffer
  - setCharAt
```
public void setCharAt(int i,
                      char ch)
```
  - setLength
```
public void setLength(int newLen)
```
  - 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)
```
  - substring
```
public String substring(int start,
                        int end)
```
  - toString
```
public String toString()
```
    Description copied from interface: CharSequence
    
    Returns the complete CharSequence as a String. Classes that implement this interface should return a String which contains only the characters in the sequence in the correct order.
    
    Specified by:
    
    toString in interface CharSequence
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    the character sequence as a String
  - trimToSize
```
public void trimToSize()
```

Class StringBuilder

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

StringBuilder

StringBuilder

StringBuilder

StringBuilder

Method Detail

append

append

append

append

append

append

append

append

append

append

append

append

append

appendCodePoint

capacity

charAt

delete

deleteCharAt

ensureCapacity

getChars

indexOf

indexOf

insert

insert

insert

insert

lastIndexOf

lastIndexOf

length

replace

reverse

setCharAt

setLength

subSequence

substring

substring

toString

trimToSize