String in JAVA 5

String in JAVA 5

StringBuilder Class

StringBuilder is identical to StringBuffer except for one important difference it is not synchronized, which means it is not thread safe. Its because StringBuilder methods are not synchronised. 

StringBuilder Constructors

1. StringBuilder (  )

2. StringBuilder ( int size )

3. StringBuilder ( String str )

1) StringBuilder ( ), creates an empty StringBuilder and reserves room for 16 characters.

2) StringBuilder ( int size ), create an empty string and takes an integer argument to set capacity of the buffer.

3) StringBuilder ( String str ), create a StringBuilder object and initialize it with string str.

Example of StringBuilder:

class Test {
 public static void main(String args[])
 {
  StringBuilder str = new StringBuilder("hello");
  str.append( "world" );
  System.out.println(str);
  str.replace( 5, 9, "java");
  System.out.println(str);
  str.reverse();
  System.out.println(str);
 }
}

Output :
helloworld 
hellojava
avajolleh

 

Difference between StringBuffer and StringBuilder Class:

StringBuffer Class	StringBuilder Class
StringBuffer is synchronized i.e. thread safe. It means two threads can't call the methods of StringBuffer simultaneously.	StringBuilder is non-synchronized i.e. not thread safe. It means two threads can call the methods of StringBuilder simultaneously.
StringBuffer is less efficient (slower) than StringBuilder.	StringBuilder is more efficient (faster) than StringBuffer.