Problems with executing code in Eclipse

Question

I was trying to execute the hello world code in Eclipse by writing main(String[]) : void in main class, but it said Error: Could not find or load main class main(String[]) : void.

Answer 1

What you've provided is only a broken fragment of a Java program. You have not fully defined a class. The most basic Java program looks like this:

public class filename{

    public static void main(String[] args){
        System.out.println("Hello, World!");
    }

}

Use this as a bare minimum for every project, and refer to Oracle's Java documentation.