StringBuffer in Java

StringBuffer

StringBuffer class is rewritable, unlike String class which is not allowed to change itself once it is declared. String is immutable. 

Methods of StringBuffer class  

1. append

StringBuffer sb = new StringBuffer("Hello ");  
sb.append("StringBuffer"); // add new string
System.out.println(sb);//prints Hello StringBuffer 

2. insert

StringBuffer sb = new StringBuffer("Hello ");  
sb.insert(3,"StringBuffer"); 
System.out.println(sb);//prints HelStringBufferlo  

3. replace

StringBuffer sb = new StringBuffer("Hello");  
sb.replace(0,2,"StringBuffer");  
System.out.println(sb);//prints StringBufferlo

4. delete

StringBuffer sb = new StringBuffer("Hello");  
sb.delete(0,1);  
System.out.println(sb);//prints llo 

Reference

https://www.javatpoint.com/StringBuffer-class