help me with this union method

[EquinoX]

I am writing a method with header like this:

public Set<E> union (Set<E> other){

}

say I have a test method:

@Test
    public void testUnion() {
        ArraySet<Integer> a = new ArraySet<Integer>(10,20);
        a.add(1);
        a.add(3);
        a.add(5);
        a.add(7);
        a.add(9);
 
        ArraySet<Integer> b = new ArraySet<Integer>(10,20);
        b.add(2);
        b.add(4);
        b.add(6);
        b.add(8);
        b.add(10);
 
        Set<Integer> c = a.union(b);
        assertEquals(10,c.size());
        for (int i = 1; i<=c.size(); i++)
            assertTrue(c.contains(i));
    }
 

how can I say the representation of a in the method body?? I know b can be represented as other in the union method head because the union method takes other as it's argument and that argument is b in this case. but what is a??

[Ganon11]

a would be referenced as this. Since you have the function as public Set..., it will be defined for each object - in this case, for Set a. Thus, the method will be called with all the variables of a in place - thus, if you had a private data member called setElements, you would simply access them by typing setElements, or this.setElements.

If you wanted to convert this function to a static function (a.k.a. not dependent on any one set), you would change the header to have 2 arguments - your function call would then look something like this:

Set<Integer> c = Set.union(a, b);

And if the header was public static Set union(Set one, Set two), you would access each element as one.setElemtents and two.setElements.