Can we pass test(null) to void display(Object o) //test is an object of the class

Question

Why null goes to method Which Accepts The String

class Test {
    public static void test(String s)
    {
        System.out.println("In String");
    }
    public static void test(Object o) {
        System.out.println("In Object");
    }

    public static void main(String args[]) {
        test(null);
    }
}

I expect The Result To be In Object as Strings Are Usually Passed in("")

I guess because `String` is the most specific match? Try adding another method that takes a `Number` as an argument and see what happens. — markspace, Jun 16 '19 at 20:11

score 1 · Answer 1 · answered Jun 16 '19 at 20:38

1

Java will always try to call the the most specific version of a method. This is part of the Java Language Specification.

Check this answer for more details and a link to the JLS: https://stackoverflow.com/a/5229890/1426538

answered Jun 16 '19 at 20:38

Asotos

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score 0 · Answer 2 · answered Jun 16 '19 at 21:06

See JLS § 15.12.2.

If more than one member method is both accessible and applicable to a method invocation, it is necessary to choose one to provide the descriptor for the run-time method dispatch. The Java programming language uses the rule that the most specific method is chosen.

The informal intuition is that one method is more specific than another if any invocation handled by the first method could be passed on to the other one without a compile-time type error.

Can we pass test(null) to void display(Object o) //test is an object of the class

2 Answers2