How to use StringBulider method in java give example,and how to create it?.

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder("java");

strb.reverse();

System.out.println(strb);//prints avaj }}

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder("Hello java");

strb.delete(1,7);

System.out.println(strb);//prints Hva }}

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder("you in java");

strb.replace(3,5,"welcome");

System.out.println(strb);//prints you welcome in java }}

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder("welcome ");

strb.append("Java");//now here original string is changed

System.out.println(strb);//prints welcome Java }}

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder("my");

strb.insert(2,"Java");//now original string is changed

System.out.println(strb);//prints myjava }}

class test{

public static void main(String args[]){

StringBuilder strb=new StringBuilder();

System.out.println(strb.capacity());//by default 16

strb.append("india");

System.out.println(strb.capacity());//now 16

strb.append("india is great");

System.out.println(strb.capacity());//now (16*2)+2=34 i.e (oldcapacity*2)+2 }}