Run a Java Program with no Main method!!!

heya! 🙂

I happened to find something really interesting…

Have you ever wondered running a simple console-based java program without a main method???

Well, its possible! It’s a trick actually, but worth a try! 🙂

Try running this…

public class NoMain {
static {
System.out.println(“Hello”);
System.exit(0);
}
}

It is done using “static initialization blocks”.

So, what is “static initializer block”?

  • A static initializer block is defined using the keyword static.
  • The code in a static initializer block is executed once by the virtual machine when the class is loaded.
  • A static initializer block cannot contain a return statement. Therefore, no need to specify a return type.
  • A static initializer block doesn’t have an argument list.
  • It can initialize only static data members of the class.

Because the static initializer block is executed when the class is first loaded, we can print out “Hello” without writing a main method. The execution is stopped using “System.exit()” command. So, we prevent “main method not found” error.

Wow!!! 🙂

cheers,

aishwarya 🙂 🙂

Courtesy: http://www.cavdar.net/2008/07/26/say-hello-world-without-main-method-in-java/

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