Void and return in Java - when to use

Question

I have some \"confusion\" about void and return. In general, I understand void is used in methods without returning anything, and return is used in methods when I want to re

Answer 1

This method :

public void add(double n)
{
   number += n;
} 

You change the internal state of number but the caller of this method doesn't know the final value of number.

In the below method, you are intimating the caller the final value of number.

public double add1(double n)
{
   return number = number +  n;
}

I would suggest to keep a separate getNumber() getter method.