Does null have Object type?

Why does this output: "inside String argument method"? Isn't null "Object" type?

class A {
    void printVal(String obj) {
        System.out.println("inside String argument method");
 开发者_如何转开发   }

    void printVal(Object obj) {
        System.out.println("inside Object argument method");
    }

    public static void main(String[] args) {
        A a = new A();
        a.printVal(null);
    }
}

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The most specific matching method will be called. More information here:

• Which overload will get selected for null in Java?

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Yes, but null is also String type and all other types, so it selects the most specific method to call.

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More specifically, a null literal will call the String version, for the reasons outlined by the other answers.

On the other hand:

class A {
    void printVal(String obj) {
        System.out.println("inside String argument method");
    }

    void printVal(Object obj) {
        System.out.println("inside Object argument method");
    }

    public static void main(String[] args) {
        A a = new A();
        Object myObj = null;
        a.printVal(myObj);
    }
}

will print "inside Object argument method." As will settings the type for myObj to any type other than String.