Strings are immutable ? is it true or not

[tue march]

Hello ppl,

I know that Strings are fixed length, immutable right.

consider the following example and explain how it achieves it.

there is string called

String s = "hello"; ok

when u apply toUpperCase() to the above string it gets changed to "HELLO".

THEN how are you saying it is not mutable. explain please.

Thanks,
good guy

[Henrik Engert]

Because toUpperCase returns a new String:

String test = "hello";
String upper = test.toUpperCase();

-Henrik

[Jan Groth]

in addition to Hendriks post:

After that opration, you'll have two objects in the heap.

"HELLO", referenced by s.
"hello", not referenced by any variable, ready to be garbage collected.

Greets,
Jan