return type of method

[Janki Shah]

class MommasPudding 
{
    public Main giveMeDaPudding(Main m) // how the return type of this method can be of other class type? 
    {
        m = null; return m;
    }
}

public class Main  
{
    int x = 10;
    public static void main(String[] args)
    { new Main().go(); }
    public void go()
    {
        MommasPudding pudding = new MommasPudding();
        pudding.giveMeDaPudding(this);
        System.out.println(this.x); // #1
    }
}

According to k&b covariant type is possible. But this class does not have a Has-A or Is-A relationship.

[gurpeet singh]

there is no obligation on the return type of the method as long as it follow java syntax rules and compiles. why are you saying that the method cannot return variable of the type Main. the co-variant type is for overridding methods. Overriding is related to inheritance. when a method overriddes another method then the overridding method can have co-variant return type ,which means its return type can be any sub-class of the return type of overridden method. there is nothing stopping you from returning object of another class from your methods.

[Janki Shah]

Thank you Gurpeet for clearing my doubt.