How to do call by reference in Java?

Question

Since Java doesnt support pointers, How is it possible to call a function by reference in Java like we do in C and C++??

Answer 1

In Java, except for primitives, passing Object to a method/function is always by reference. See Oli Charlesworth's answer for the example.

For primitive types, you can wrap it using array: For example:

public void foo(int[] in){
  in[0] = 2;
}

int[] byRef = new int[1];
byRef[0] = 1;
foo(byRef);
// ==> byRef[0] == 2.