Question

Here’s my question, how can I change an object outside of it’s class, so that it maintains the changes made in the outside class?

Here’s an example of the code:

Main class:

    public class Main {

        public static void main(String[] args)
        {
            Variable var = new Variable(1,2,3);
            Change.changeVar(var);
            System.out.println("" + var.geta() + "" + var.getb() + "" + var.getc());
        }
    }

Variable class:

public class Variable {

private int a;
private int b;
private int c;

public Variable(int a, int b, int c)
{
    this.a = a;
    this.b = b;
    this.c = c;
}

public int geta()
{
    return this.a;
}

public int getb()
{
    return this.b;
}

public int getc()
{
    return this.c;
}

}

Change class:

public class Change {

public static void changeVar(Variable var)
{
    Variable var2 = new Variable(4,5,6);
    var = var2;
}

}

Answer 1

In your example, no. When changeVar() exits, the parameter var is discarded, and the var in your main() method retains its original value. Read up on pass by reference.