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

It's also worthwhile to note that since strings are immutable, that if they are passed into a method, they can't be modified inside of the method and then have those changes seen outside of the method scope.

public void changeIt(String s) {
    // I can't do anything to s here that changes the value 
    // original string object passed into this method
} 

public void changeIt(SomeObject o) {
    // if SomeObject is mutable, I can do things to it that will 
    // be visible outside of this method call
}