String vs Object

[mvPrasad Regula]

Why is the code below printing String version, as both String and Object accept null value.

   public void method(Object o)
     {
         System.out.println("Object Verion");
     }
 public void method(String s)
 {
    System.out.println("String Version");
 }
    public static void main(String[] args) {
          Main question = new Main();
     question.method(null);
    }  

[Bear Bibeault]

"myPrasad Regula", please check your private messages for an important administrative matter or your account will be removed.

[Abimaran Kugathasan]

If I able to reply....
Check the code below......

    
class CheckObjectHierAndNull	{
	public void method(A a)	{
		System.out.println("A");
	}
	public void method(C c)	{
		System.out.println("C"); // C will be print..
	}
	public void method(Object o)	{
		System.out.println("Object");
	}
	public void method(B a)	{
		System.out.println("B");
	}

	public static void main(String[] args)	{
		CheckObjectHierAndNull oj = new CheckObjectHierAndNull();
		oj.method(null);
	}
}

class A	{}
class B extends A	{}
class C extends B	{}

The method, which has the lower place in the hierarchy will be invoked..... In this example, Class C is the lowest class in the hierarchy. So the method with that type of parameter will be invoked. Same for your coding, as String is a sub class of Object.......

[Harpreet Singh janda]

Yes, Abimaran Kugathasan is right. Always more specific version of method is called and because whenever you are coming down in a hierarchy you a more specific about the class. So always the method with argument of lowest level of the hierarchy is called.

[Abimaran Kugathasan]

[Muhammad Khojaye]

See also this FAQ