public final class StringBuilder extends Objectimplements Serializable , CharSequence
StringBuffer
, but with no guarantee of synchronization. This class is designed for use as a drop-in replacement for
StringBuffer
in places where the string buffer was being used by a single thread (as is generally the case). Where possible, it is recommended that this class be used in preference to
StringBuffer
as it will be faster under most implementations.
The principal operations on a StringBuilder
are the append
and insert
methods, which are overloaded so as to accept data of any type. Each effectively converts a given datum to a string and then appends or inserts the characters of that string to the string builder. The append
method always adds these characters at the end of the builder; the insert
method adds the characters at a specified point.
For example, if z
refers to a string builder object whose current contents are "start
", then the method call z.append("le")
would cause the string builder to contain "startle
", whereas z.insert(4, "le")
would alter the string builder to contain "starlet
".
In general, if sb refers to an instance of a StringBuilder
, then sb.append(x)
has the same effect as sb.insert(sb.length(), x)
.
Every string builder has a capacity. As long as the length of the character sequence contained in the string builder does not exceed the capacity, it is not necessary to allocate a new internal buffer. If the internal buffer overflows, it is automatically made larger.
Instances of StringBuilder
are not safe for use by multiple threads. If such synchronization is required then it is recommended that StringBuffer
be used.
Unless otherwise noted, passing a null
argument to a constructor or method in this class will cause a NullPointerException
to be thrown.
StringBuffer
,
String
,
Serialized Form
Constructor and Description |
---|
StringBuilder()
Constructs a string builder with no characters in it and an initial capacity of 16 characters.
|
StringBuilder(CharSequence
Constructs a string builder that contains the same characters as the specified
CharSequence .
|
StringBuilder(int capacity)
Constructs a string builder with no characters in it and an initial capacity specified by the
capacity argument.
|
StringBuilder(String
Constructs a string builder initialized to the contents of the specified string.
|
Modifier and Type | Method and Description |
---|---|
StringBuilder |
append(boolean b)
Appends the string representation of the
boolean argument to the sequence.
|
StringBuilder |
append(char c)
Appends the string representation of the
char argument to this sequence.
|
StringBuilder |
append(char[] str)
Appends the string representation of the
char array argument to this sequence.
|
StringBuilder |
append(char[] str, int offset, int len)
Appends the string representation of a subarray of the
char array argument to this sequence.
|
StringBuilder |
append(CharSequence
Appends the specified character sequence to this
Appendable.
|
StringBuilder |
append(CharSequence
Appends a subsequence of the specified
CharSequence to this sequence.
|
StringBuilder |
append(double d)
Appends the string representation of the
double argument to this sequence.
|
StringBuilder |
append(float f)
Appends the string representation of the
float argument to this sequence.
|
StringBuilder |
append(int i)
Appends the string representation of the
int argument to this sequence.
|
StringBuilder |
append(long lng)
Appends the string representation of the
long argument to this sequence.
|
StringBuilder |
append(Object
Appends the string representation of the
Object argument.
|
StringBuilder |
append(String
Appends the specified string to this character sequence.
|
StringBuilder |
append(StringBuffer
Appends the specified
StringBuffer to this sequence.
|
StringBuilder |
appendCodePoint(int codePoint)
Appends the string representation of the
codePoint argument to this sequence.
|
int |
capacity()
Returns the current capacity.
|
char |
charAt(int index)
Returns the
char value in this sequence at the specified index.
|
int |
codePointAt(int index)
Returns the character (Unicode code point) at the specified index.
|
int |
codePointBefore(int index)
Returns the character (Unicode code point) before the specified index.
|
int |
codePointCount(int beginIndex, int endIndex)
Returns the number of Unicode code points in the specified text range of this sequence.
|
StringBuilder |
delete(int start, int end)
Removes the characters in a substring of this sequence.
|
StringBuilder |
deleteCharAt(int index)
Removes the
char at the specified position in this sequence.
|
void |
ensureCapacity(int minimumCapacity)
Ensures that the capacity is at least equal to the specified minimum.
|
void |
getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
Characters are copied from this sequence into the destination character array
dst .
|
int |
indexOf(String
Returns the index within this string of the first occurrence of the specified substring.
|
int |
indexOf(String
Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.
|
StringBuilder |
insert(int offset, boolean b)
Inserts the string representation of the
boolean argument into this sequence.
|
StringBuilder |
insert(int offset, char c)
Inserts the string representation of the
char argument into this sequence.
|
StringBuilder |
insert(int offset, char[] str)
Inserts the string representation of the
char array argument into this sequence.
|
StringBuilder |
insert(int index, char[] str, int offset, int len)
Inserts the string representation of a subarray of the
str array argument into this sequence.
|
StringBuilder |
insert(int dstOffset, CharSequence
Inserts the specified
CharSequence into this sequence.
|
StringBuilder |
insert(int dstOffset, CharSequence
Inserts a subsequence of the specified
CharSequence into this sequence.
|
StringBuilder |
insert(int offset, double d)
Inserts the string representation of the
double argument into this sequence.
|
StringBuilder |
insert(int offset, float f)
Inserts the string representation of the
float argument into this sequence.
|
StringBuilder |
insert(int offset, int i)
Inserts the string representation of the second
int argument into this sequence.
|
StringBuilder |
insert(int offset, long l)
Inserts the string representation of the
long argument into this sequence.
|
StringBuilder |
insert(int offset, Object
Inserts the string representation of the
Object argument into this character sequence.
|
StringBuilder |
insert(int offset, String
Inserts the string into this character sequence.
|
int |
lastIndexOf(String
Returns the index within this string of the rightmost occurrence of the specified substring.
|
int |
lastIndexOf(String
Returns the index within this string of the last occurrence of the specified substring.
|
int |
length()
Returns the length (character count).
|
int |
offsetByCodePoints(int index, int codePointOffset)
Returns the index within this sequence that is offset from the given
index by
codePointOffset code points.
|
StringBuilder |
replace(int start, int end, String
Replaces the characters in a substring of this sequence with characters in the specified
String .
|
StringBuilder |
reverse()
Causes this character sequence to be replaced by the reverse of the sequence.
|
void |
setCharAt(int index, char ch)
The character at the specified index is set to
ch .
|
void |
setLength(int newLength)
Sets the length of the character sequence.
|
CharSequence |
subSequence(int start, int end)
Returns a new character sequence that is a subsequence of this sequence.
|
String |
substring(int start)
Returns a new
String that contains a subsequence of characters currently contained in this character sequence.
|
String |
substring(int start, int end)
Returns a new
String that contains a subsequence of characters currently contained in this sequence.
|
String |
toString()
Returns a string representing the data in this sequence.
|
void |
trimToSize()
Attempts to reduce storage used for the character sequence.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
charAt, chars, codePoints, length, subSequence
public StringBuilder()
public StringBuilder(int capacity)
capacity
argument.
capacity
- the initial capacity.
NegativeArraySizeException
- if the
capacity
argument is less than
0
.
public StringBuilder(Stringstr)
16
plus the length of the string argument.
str
- the initial contents of the buffer.
public StringBuilder(CharSequenceseq)
CharSequence
. The initial capacity of the string builder is
16
plus the length of the
CharSequence
argument.
seq
- the sequence to copy.
public StringBuilderappend(Object obj)
Object
argument.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
obj
- an
Object
.
public StringBuilderappend(String str)
The characters of the String
argument are appended, in order, increasing the length of this sequence by the length of the argument. If str
is null
, then the four characters "null"
are appended.
Let n be the length of this character sequence just prior to execution of the append
method. Then the character at index k in the new character sequence is equal to the character at index k in the old character sequence, if k is less than n; otherwise, it is equal to the character at index k-n in the argument str
.
str
- a string.
public StringBuilderappend(StringBuffer sb)
StringBuffer
to this sequence.
The characters of the StringBuffer
argument are appended, in order, to this sequence, increasing the length of this sequence by the length of the argument. If sb
is null
, then the four characters "null"
are appended to this sequence.
Let n be the length of this character sequence just prior to execution of the append
method. Then the character at index k in the new character sequence is equal to the character at index k in the old character sequence, if k is less than n; otherwise, it is equal to the character at index k-n in the argument sb
.
sb
- the
StringBuffer
to append.
public StringBuilderappend(CharSequence s)
Appendable
Depending on which class implements the character sequence csq, the entire sequence may not be appended. For instance, if csq is a CharBuffer
then the subsequence to append is defined by the buffer's position and limit.
append
in interface
Appendable
s
- The character sequence to append. If
csq is
null, then the four characters
"null" are appended to this Appendable.
public StringBuilderappend(CharSequence s, int start, int end)
CharSequence
to this sequence.
Characters of the argument s
, starting at index start
, are appended, in order, to the contents of this sequence up to the (exclusive) index end
. The length of this sequence is increased by the value of end - start
.
Let n be the length of this character sequence just prior to execution of the append
method. Then the character at index k in this character sequence becomes equal to the character at index k in this sequence, if k is less than n; otherwise, it is equal to the character at index k+start-n in the argument s
.
If s
is null
, then this method appends characters as if the s parameter was a sequence containing the four characters "null"
.
append
in interface
Appendable
s
- the sequence to append.
start
- the starting index of the subsequence to be appended.
end
- the end index of the subsequence to be appended.
IndexOutOfBoundsException
- if
start
is negative, or
start
is greater than
end
or
end
is greater than
s.length()
public StringBuilderappend(char[] str)
char
array argument to this sequence.
The characters of the array argument are appended, in order, to the contents of this sequence. The length of this sequence increases by the length of the argument.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
str
- the characters to be appended.
public StringBuilderappend(char[] str, int offset, int len)
char
array argument to this sequence.
Characters of the char
array str
, starting at index offset
, are appended, in order, to the contents of this sequence. The length of this sequence increases by the value of len
.
The overall effect is exactly as if the arguments were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
str
- the characters to be appended.
offset
- the index of the first
char
to append.
len
- the number of
char
s to append.
IndexOutOfBoundsException
- if
offset < 0
or
len < 0
or
offset+len > str.length
public StringBuilderappend(boolean b)
boolean
argument to the sequence.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
b
- a
boolean
.
public StringBuilderappend(char c)
char
argument to this sequence.
The argument is appended to the contents of this sequence. The length of this sequence increases by 1
.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the character in that string were then appended
to this character sequence.
append
in interface
Appendable
c
- a
char
.
public StringBuilderappend(int i)
int
argument to this sequence.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
i
- an
int
.
public StringBuilderappend(long lng)
long
argument to this sequence.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
lng
- a
long
.
public StringBuilderappend(float f)
float
argument to this sequence.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
f
- a
float
.
public StringBuilderappend(double d)
double
argument to this sequence.
The overall effect is exactly as if the argument were converted to a string by the method String
, and the characters of that string were then appended
to this character sequence.
d
- a
double
.
public StringBuilderappendCodePoint(int codePoint)
codePoint
argument to this sequence.
The argument is appended to the contents of this sequence. The length of this sequence increases by Character.charCount(codePoint)
.
The overall effect is exactly as if the argument were converted to a char
array by the method Character
and the character in that array were then appended
to this character sequence.
codePoint
- a Unicode code point
public StringBuilderdelete(int start, int end)
start
and extends to the character at index
end - 1
or to the end of the sequence if no such character exists. If
start
is equal to
end
, no changes are made.
start
- The beginning index, inclusive.
end
- The ending index, exclusive.
StringIndexOutOfBoundsException
- if
start
is negative, greater than
length()
, or greater than
end
.
public StringBuilderdeleteCharAt(int index)
char
at the specified position in this sequence. This sequence is shortened by one
char
.
Note: If the character at the given index is a supplementary character, this method does not remove the entire character. If correct handling of supplementary characters is required, determine the number of char
s to remove by calling Character.charCount(thisSequence.codePointAt(index))
, where thisSequence
is this sequence.
index
- Index of
char
to remove
StringIndexOutOfBoundsException
- if the
index
is negative or greater than or equal to
length()
.
public StringBuilderreplace(int start, int end, String str)
String
. The substring begins at the specified
start
and extends to the character at index
end - 1
or to the end of the sequence if no such character exists. First the characters in the substring are removed and then the specified
String
is inserted at
start
. (This sequence will be lengthened to accommodate the specified String if necessary.)
start
- The beginning index, inclusive.
end
- The ending index, exclusive.
str
- String that will replace previous contents.
StringIndexOutOfBoundsException
- if
start
is negative, greater than
length()
, or greater than
end
.
public StringBuilderinsert(int index, char[] str, int offset, int len)
str
array argument into this sequence. The subarray begins at the specified
offset
and extends
len
char
s. The characters of the subarray are inserted into this sequence at the position indicated by
index
. The length of this sequence increases by
len
char
s.
index
- position at which to insert subarray.
str
- A
char
array.
offset
- the index of the first
char
in subarray to be inserted.
len
- the number of
char
s in the subarray to be inserted.
StringIndexOutOfBoundsException
- if
index
is negative or greater than
length()
, or
offset
or
len
are negative, or
(offset+len)
is greater than
str.length
.
public StringBuilderinsert(int offset, Object obj)
Object
argument into this character sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
obj
- an
Object
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, String str)
The characters of the String
argument are inserted, in order, into this sequence at the indicated offset, moving up any characters originally above that position and increasing the length of this sequence by the length of the argument. If str
is null
, then the four characters "null"
are inserted into this sequence.
The character at index k in the new character sequence is equal to:
offset
-offset
in the argument str
, if k is not less than offset
but is less than offset+str.length()
-str.length()
in the old character sequence, if k is not less than offset+str.length()
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
str
- a string.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, char[] str)
char
array argument into this sequence.
The characters of the array argument are inserted into the contents of this sequence at the position indicated by offset
. The length of this sequence increases by the length of the argument.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
str
- a character array.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int dstOffset, CharSequence s)
CharSequence
into this sequence.
The characters of the CharSequence
argument are inserted, in order, into this sequence at the indicated offset, moving up any characters originally above that position and increasing the length of this sequence by the length of the argument s.
The result of this method is exactly the same as if it were an invocation of this object's insert
(dstOffset, s, 0, s.length()) method.
If s
is null
, then the four characters "null"
are inserted into this sequence.
dstOffset
- the offset.
s
- the sequence to be inserted
IndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int dstOffset, CharSequence s, int start, int end)
CharSequence
into this sequence.
The subsequence of the argument s
specified by start
and end
are inserted, in order, into this sequence at the specified destination offset, moving up any characters originally above that position. The length of this sequence is increased by end - start
.
The character at index k in this sequence becomes equal to:
dstOffset
+start-dstOffset
in the argument s
, if k is greater than or equal to dstOffset
but is less than dstOffset+end-start
-(end-start)
in this sequence, if k is greater than or equal to dstOffset+end-start
The dstOffset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
The start argument must be nonnegative, and not greater than end
.
The end argument must be greater than or equal to start
, and less than or equal to the length of s.
If s
is null
, then this method inserts characters as if the s parameter was a sequence containing the four characters "null"
.
dstOffset
- the offset in this sequence.
s
- the sequence to be inserted.
start
- the starting index of the subsequence to be inserted.
end
- the end index of the subsequence to be inserted.
IndexOutOfBoundsException
- if
dstOffset
is negative or greater than
this.length()
, or
start
or
end
are negative, or
start
is greater than
end
or
end
is greater than
s.length()
public StringBuilderinsert(int offset, boolean b)
boolean
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
b
- a
boolean
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, char c)
char
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the character in that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
c
- a
char
.
IndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, int i)
int
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
i
- an
int
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, long l)
long
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
l
- a
long
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, float f)
float
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
f
- a
float
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public StringBuilderinsert(int offset, double d)
double
argument into this sequence.
The overall effect is exactly as if the second argument were converted to a string by the method String
, and the characters of that string were then inserted
into this character sequence at the indicated offset.
The offset
argument must be greater than or equal to 0
, and less than or equal to the length of this sequence.
offset
- the offset.
d
- a
double
.
StringIndexOutOfBoundsException
- if the offset is invalid.
public int indexOf(Stringstr)
this.toString().startsWith(str, <i>k</i>)
is
true
.
str
- any string.
-1
is returned.
public int indexOf(Stringstr, int fromIndex)
k
for which:
k >= Math.min(fromIndex, this.length()) && this.toString().startsWith(str, k)
If no such value of
k exists, then -1 is returned.
str
- the substring for which to search.
fromIndex
- the index from which to start the search.
public int lastIndexOf(Stringstr)
this.length()
. The returned index is the largest value
k such that
this.toString().startsWith(str, k)
is true.
str
- the substring to search for.
-1
is returned.
public int lastIndexOf(Stringstr, int fromIndex)
k <= Math.min(fromIndex, this.length()) && this.toString().startsWith(str, k)
If no such value of
k exists, then -1 is returned.
str
- the substring to search for.
fromIndex
- the index to start the search from.
public StringBuilderreverse()
char
values) just prior to execution of the
reverse
method. Then the character at index
k in the new character sequence is equal to the character at index
n-k-1 in the old character sequence.
Note that the reverse operation may result in producing surrogate pairs that were unpaired low-surrogates and high-surrogates before the operation. For example, reversing "\uDC00\uD800" produces "\uD800\uDC00" which is a valid surrogate pair.
public StringtoString()
String
object is allocated and initialized to contain the character sequence currently represented by this object. This
String
is then returned. Subsequent changes to this sequence do not affect the contents of the
String
.
toString
in interface
CharSequence
public int length()
length
in interface
CharSequence
public int capacity()
public void ensureCapacity(int minimumCapacity)
minimumCapacity
argument. 2
. minimumCapacity
argument is nonpositive, this method takes no action and simply returns. Note that subsequent operations on this object can reduce the actual capacity below that requested here.
minimumCapacity
- the minimum desired capacity.
public void trimToSize()
capacity()
method.
public void setLength(int newLength)
newLength
, the character at index
k in the new character sequence is the same as the character at index
k in the old sequence if
k is less than the length of the old character sequence; otherwise, it is the null character
'\u0000'
. In other words, if the
newLength
argument is less than the current length, the length is changed to the specified length.
If the newLength
argument is greater than or equal to the current length, sufficient null characters ('\u0000'
) are appended so that length becomes the newLength
argument.
The newLength
argument must be greater than or equal to 0
.
newLength
- the new length
IndexOutOfBoundsException
- if the
newLength
argument is negative.
public char charAt(int index)
char
value in this sequence at the specified index. The first
char
value is at index
0
, the next at index
1
, and so on, as in array indexing.
The index argument must be greater than or equal to 0
, and less than the length of this sequence.
If the char
value specified by the index is a surrogate, the surrogate value is returned.
charAt
in interface
CharSequence
index
- the index of the desired
char
value.
char
value at the specified index.
IndexOutOfBoundsException
- if
index
is negative or greater than or equal to
length()
.
public int codePointAt(int index)
char
values (Unicode code units) and ranges from
0
to
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 sequence, 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.
index
- the index to the
char
values
index
IndexOutOfBoundsException
- if the
index
argument is negative or not less than the length of this sequence.
public int codePointBefore(int index)
char
values (Unicode code units) and ranges from
1
to
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.
index
- the index following the code point that should be returned
IndexOutOfBoundsException
- if the
index
argument is less than 1 or greater than the length of this sequence.
public int codePointCount(int beginIndex, int endIndex)
beginIndex
and extends to the
char
at index
endIndex - 1
. Thus the length (in
char
s) of the text range is
endIndex-beginIndex
. Unpaired surrogates within this sequence count as one code point each.
beginIndex
- the index to the first
char
of the text range.
endIndex
- the index after the last
char
of the text range.
IndexOutOfBoundsException
- if the
beginIndex
is negative, or
endIndex
is larger than the length of this sequence, or
beginIndex
is larger than
endIndex
.
public int offsetByCodePoints(int index, int codePointOffset)
index
by
codePointOffset
code points. Unpaired surrogates within the text range given by
index
and
codePointOffset
count as one code point each.
index
- the index to be offset
codePointOffset
- the offset in code points
IndexOutOfBoundsException
- if
index
is negative or larger then the length of this sequence, or if
codePointOffset
is positive and the subsequence starting with
index
has fewer than
codePointOffset
code points, or if
codePointOffset
is negative and the subsequence before
index
has fewer than the absolute value of
codePointOffset
code points.
public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
dst
. 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 are copied into the subarray of
dst
starting at index
dstBegin
and ending at index:
dstbegin + (srcEnd-srcBegin) - 1
srcBegin
- start copying at this offset.
srcEnd
- stop copying at this offset.
dst
- the array to copy the data into.
dstBegin
- offset into
dst
.
IndexOutOfBoundsException
- if any of the following is true:
srcBegin
is negative dstBegin
is negative srcBegin
argument is greater than the srcEnd
argument. srcEnd
is greater than this.length()
. dstBegin+srcEnd-srcBegin
is greater than dst.length
public void setCharAt(int index, char ch)
ch
. This sequence is altered to represent a new character sequence that is identical to the old character sequence, except that it contains the character
ch
at position
index
.
The index argument must be greater than or equal to 0
, and less than the length of this sequence.
index
- the index of the character to modify.
ch
- the new character.
IndexOutOfBoundsException
- if
index
is negative or greater than or equal to
length()
.
public Stringsubstring(int start)
String
that contains a subsequence of characters currently contained in this character sequence. The substring begins at the specified index and extends to the end of this sequence.
start
- The beginning index, inclusive.
StringIndexOutOfBoundsException
- if
start
is less than zero, or greater than the length of this object.
public CharSequencesubSequence(int start, int end)
An invocation of this method of the form
sb.subSequence(begin, end)
behaves in exactly the same way as the invocation
sb.substring(begin, end)
This method is provided so that this class can implement the
CharSequence
interface.
subSequence
in interface
CharSequence
start
- the start index, inclusive.
end
- the end index, exclusive.
IndexOutOfBoundsException
- if
start
or
end
are negative, if
end
is greater than
length()
, or if
start
is greater than
end
public Stringsubstring(int start, int end)
String
that contains a subsequence of characters currently contained in this sequence. The substring begins at the specified
start
and extends to the character at index
end - 1
.
start
- The beginning index, inclusive.
end
- The ending index, exclusive.
StringIndexOutOfBoundsException
- if
start
or
end
are negative or greater than
length()
, or
start
is greater than
end
.