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Today, I will talk to you about how to understand the accuracy of myMethod in Java. Many people may not know much about it. In order to make you understand better, the editor has summarized the following for you. I hope you can get something according to this article.

When I saw a question on Douyin, I thought it was very interesting. I haven't thought about it carefully before. I'd like to share it with you here.

Public class TestObjectString {

Public void myMethod (String str) {

System.out.println ("String")

}

Public void myMethod (Object obj) {

System.out.println ("Object")

}

Public static void main (String [] args) {

TestObjectString t = new TestObjectString ()

T.myMethod (null)

}

}

At first glance, the parameter passed to the method is an empty object reference, so at first glance, it seems that the program should call an overloaded version with the parameter type Object

And Object will be printed out. On the other hand, String is also a reference type, so null can also be applied to overloaded versions of type String.

You may conclude that the call is ambiguous and that the program should not be compiled. If you try to run the program,

You will find that these intuitive feelings are wrong: the program prints String.

The overloaded parsing process of ava runs in two phases. In the first stage, all available and applicable methods or constructors are selected. In the method or constructor selected in the first stage.

Choose the most accurate one. If one method or constructor can accept any parameters passed to another method or constructor, then we say that the first method is less accurate than the second method.

In our program, both methods are available and applicable. The method constructor myMethod (Object) can accept any parameter passed to myMethod (String)

Therefore, myMethod (Object) is relatively inaccurate. Every String is an Object, but every Object is not necessarily a String. ) therefore

The most accurate method is myMethod (String), which explains why the program produces such output. How to output Object you can call myMethod ((Object) null) like this.

After reading the above, do you have any further understanding of how to understand the accuracy of myMethod in Java? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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