String can't change. But int, char can change

Question

I\'ve read that in Java an object of type String can\'t change. But int and char variables can. Why is it? Can you give me an example?

Thank you. (I am a newer -_- )

Answer 1

String is an immutable type (the value inside of it cannot change). The same is true for all primitive types (boolean, byte, char, short, int, long, float, and double).

int    x;
String s;

x = 1;
x = 2;
s = "hello";
s = "world";
x++; // x = x + 1;
x--; // x = x - 1;

As you can see, in no case can you alter the constant value (1, 2, "hello", "world") but you can alter where they are pointing (if you warp your mind a bit and say that an int variable points at a constant int value).