Does modifying the result of a getter affect the object itself?

Question

I have a question about using getter methods in java. Suppose I had this class:

class Test {
    private ArrayList<String> array = new ArrayList<String>();

    public ArrayList getArray() {
        return this.array;
    }

    public void initArray() {
        array.add("Test 1");
        array.add("Test 2");
    }
}

class Start {
    public static void main(String args[]) {
        initArray();
        getArray().remove(0);
    }
} 

My question is:

Would the actual arraylist object be modified ("Test 1" removed from it)? I think I have seen this in places, but I thought that getters were simply providing a copy of that object. Not a reference to it. If it did work that way (as a reference), then would this work as well (Would the arraylist object of the class Test be altered by this as well)?:

class Start {
    public static void main(String args[]) {
        initArray();
        ArrayList aVar = getArray();
        aVar.remove(0);
    }
} 

Answer 1

Java returns references to the Array, so it won't be a copy and it will modify the List. In general, unless its a primitive type (int,float,etc) you will be getting a reference to the object.

You have to explicitly copy the array yourself if you want a duplicate to be returned.

Answer 2

The way I understand it, Object reference variables are little more than memory addresses of the objects themselves. So what is returned from getArray() is a reference variable to that ArrayList. An object may have many reference variables, but it is still the same object that gets modified.

Java does everything pass by value. So anytime you pass an object reference variable as a parameter or return it's value, you are passing or returning the value of the object reference variable.