String vs StringBuffer vs StringBuilder

	String	StringBuffer	StringBuilder
Storage Area	Constant String Pool	Heap	Heap
Modifiable	No (immutable)	Yes (mutable)	Yes (mutable)
Thread Safe	Yes Every immutable object in Java is Thread safe.	Yes All method synchronized.	No
Performance	Fast	Very slow All method synchronized.	Fast
Example	String  demo = "hello " ; demo = “bye”; "hello" string still exists in string constant pool. new "Bye" string is created in constant pool and referenced by the demo variable.	StringBuffer demo = new StringBuffer("Hello"); Object stored in heap and its value can be changed. demo=new StringBuffer("Bye");	StringBuilder demo = new StringBuilder ("Hello"); Object stored in heap and its value can be changed. demo=new StringBuilder ("Bye");