How to implement int in/out params in java

Question

Apologies for asking such a primitive question.

I wrote a function which took one parameter; this parameter was supposed to be an in/out parameter.

After d

Answer 1

Answer 1:

One approach would be to pass in an AtomicInteger, which is mutable.

boolean getNextFoo(AtomicInteger foo) {
  foo.set(foo.get() + 1);
  return true;
}

Answer 2:

The statement: currentFoo = currentFoo + 1 is not modifying the object; it is creating a new Integer instance and reassigning the local reference to point to it.

When you exit from the method the local reference is "lost" (i.e. it goes out of scope) and hence reassigning it has no effect outside of the method.