In java, if I call, from a subclass, a superclass method that calls an overriden method, which class' method will be called?

Question

Say I have this Super Class:

public class MySuperClass {

protected void MyPrMethod() {
        //Do...
    }

    public void MyPuMethod() {
        MyPrMethod();
    }
}

and this Sub Class:

public class MySubClass extends MeSuperClass {
    public MySubClass() {}

    @Override protected void MyPrMethod() {
        //Do this instead...
    }
}

Then into main:

MySubClass mySubClass = new MySubClass ();
mySubClass.MyPuMethod();

Which MyPrMethod will mySubClass.MyPuMethod() call?

Edit: I got downvoted thrice already. I cannot try it now since I am not at home, though knowing the answer right now will help me designing a part in a program I am making.

I am not at home so I can't try it now, but if I have the answer now, I'll be able to continue designing a part of a program I am making. Else I would have tried it. — Mickael Bergeron Néron, Jul 17 '13 at 21:06
See this question: [http://stackoverflow.com/q/4595512/292442](http://stackoverflow.com/q/4595512/292442) — Rachel, Jul 17 '13 at 21:08
@MickaelBergeronNéron http://www.compileonline.com/compile_java_online.php — Brian Roach, Jul 17 '13 at 21:08

Andy Thomas · Accepted Answer · 2013-07-17T21:11:29.960

3

Because the method MyPrMethod() is overridden in the subclass, the subclass implementation will be called.

The actual method that gets called depends on the object on which it gets called.

edited Jul 17 '13 at 21:11

answered Jul 17 '13 at 21:06

Andy Thomas

84,978
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score 2 · Answer 2 · answered Jul 17 '13 at 21:08

2

The subclass's version of the method will be used. When MyPuMethod calls MyPrMethod, the class (MySubClass) is first checked for the desired method, and only if it's not defined there are the parents recursively searched. The fact that the method we're currently executing is defined in a different class does not change this.

answered Jul 17 '13 at 21:08

Asterlune

59
3

At runtime, no search should occur. The object's class can reference a vtable of the virtual methods it supports. – Andy Thomas Jul 17 '13 at 21:47

score 1 · Answer 3 · answered Jul 17 '13 at 21:09

1

The MyPrMethod from subclass MySubClass will get called.

answered Jul 17 '13 at 21:09

rvd

157
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In java, if I call, from a subclass, a superclass method that calls an overriden method, which class' method will be called?

3 Answers3