Help Required In case of Strings

Question

Hi,
I execured following code. And as in java references of the objects get passes the output of the program should be "hi" and not "hello". Can anyone explain why this is so..
public class Test {
public static void main(String args[]){
new Test().fun1();
public void fun1(){
String str = "hello";
fun2(str);
System.out.println("str="+str);
public void fun2(String str){
str = "hi";

Answer 1

This one is different because you are altering the CONTENTS of A.
Strings are immutable - you can never change their contents.
A is not immutable - you can change the attribute of A. Any changes you make to the values INSIDE A, get reflected in the calling method.
Try this one though:
void fun3(A a)
a = new A();
a.str="ABCfun2";
}This is the equivalent of your first example. a is treated as a local variable. If you assign something to a, it won't change the value in the calling method. If you manipulate the contents of a, those changes come through.