Difference between string and string builder.

Answer 1

we are going to understand the difference between String , StringBuilder and StringBuffer :

String is immutable (once created can not be changed)object . The object created as a String is stored in the Constant String Pool .

StringBuffer is mutable means one can change the value of the object . The object created through StringBuffer is stored in the heap . StringBuffer has the same methods as the StringBuilder , but each method in StringBuffer is synchronized that is StringBuffer is thread safe .

StringBuilder is same as the StringBuffer , that is it stores the object in heap and it can also be modified . The main difference between the StringBuffer and StringBuilder is that StringBuilder is also not thread safe.
StringBuilder is fast as it is not thread safe .

hope can help you .

Answer 2

yaa I corrected my mistake

Answer 3

Sumit is mostly right. StringBuilder is not synchronized. It is StringBuffer which is synchronized.

https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuilder.html

Answer 4

String is immutable , StringBuilder is mutable and nonSynchronized and there is one more term StringBuffer which is same as StringBuilder but is Synchronised . immutable means you can't modify it
and Synchronized means its thread safe though StringBuilder is faster than StringBuffer.