java RuntimeException and compiler error

Question

In the following code when i chaged the return type then it did not give the compiler error just throw runtime exception.Is it not the syntex error to give the wrong return type of long instead of void.

class Jfilestr {
    public static long main(String[] args) {
        System.out.println("Hello");      
        return 10L;

        //It will give the runtime exception.
        /*Error: Main method must return a value of type void in class Jfilestr, please
        define the main method as:
         public static void main(String[] args)*/
    }
}

What error do you get when you put the right return type, i.e `void` ? Note that of course you can't `return` a value when the method is `void` . — Arnaud, May 11 '18 at 13:05
the error is pretty straightforward: the `main` method must return void. Period. — HBo, May 11 '18 at 13:05
The Error message is telling you exactly what you need to do =) — Morgan, May 11 '18 at 13:06
https://stackoverflow.com/questions/13603445/legal-main-method-signature-in-java — Nikesh Joshi, May 11 '18 at 13:06
You may want [System.exit](https://docs.oracle.com/javase/7/docs/api/java/lang/System.html#exit%28int%29) — 001, May 11 '18 at 13:09

Steve11235 · Answer 1 · 2018-05-11T16:05:12.860

0

Your problem is that

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

plays a special role in Java. It is the entry point when you start a Java application. Technically, you can create the method you described, but won't function as an entry point. This happens often enough that the runtime detects the error and tells you what you did.

You can't return a value from the entry point method.

edited May 11 '18 at 16:05

answered May 11 '18 at 13:08

Steve11235

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I see what you are getting at. The java call specified the class, and it is smart enough to detect an invalid main. I'll update my answer. Thanks. – Steve11235 May 11 '18 at 16:03

java RuntimeException and compiler error

1 Answers1