Question

Is there any difference between:

String x = getString();
doSomething(x);

vs.

doSomething(getString());

Resources and performance wise, Especially is it’s done within a loop for tens, hundreds or thousands of times?

Answer 1

It has the same overhead. Local variables are just there to make your life easier. At the VM level they don’t necessarily exist and certainly not anymore when machine code is run.

So what you need to worry about here is getString(), whether it is potentially expensive. x has very likely no effect at all.