THE PACKAGE JAVA.LANG

java.lang.StringBuffer

20.13

argument. If

str

 is

null

, then the four characters  

null

  are appended to this

string buffer. The method

ensureCapacity

 ( 20.13.7) is first called with this new

string buffer length as its argument. A reference to this

StringBuffer

 object is

returned.

Let

n

 be the length of the old character sequence, the one contained in the

string buffer 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

.

20.13.14

public StringBuffer append(char[] str)

throws NullPointerException

The characters of the array argument are appended, in order, to the contents of this

string buffer, increasing the length of this string buffer by the length of the argu 

ment. The method

ensureCapacity

 ( 20.13.7) is first called with this new string

buffer length as its argument. A reference to this

StringBuffer

 object is

returned.

The overall effect is exactly as if the argument were converted to a string by

the method

String.valueOf

 ( 20.12.39) and the characters of that string were

then appended ( 20.13.13) to this

StringBuffer

 object.

20.13.15

public StringBuffer append(char[] str,

int offset, int len)

throws NullPointerException,

IndexOutOfBoundsException

Characters of the character array

str

, starting at index

offset

, are appended, in

order, to the contents of this string buffer, increasing the length of this string

buffer by

len

. The method

ensureCapacity

 ( 20.13.7) is first called with this

new string buffer length as its argument. A reference to this

StringBuffer

 object

is returned.

The overall effect is exactly as if the arguments were converted to a string by

the method

String.valueOf

 of three arguments ( 20.12.40) and the characters

of that string were then appended ( 20.13.13) to this

StringBuffer

 object.

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