What is missing here

Question

https://code.sololearn.com/cnfdFmrWy1sD/?ref=app

Answer 1

Main method

Answer 2

Program execution in java starts from main method. With out main method, your program won't run.
You created a class and inner class. To use these, you need to call it. That is possible from main method of main class.

Remove first line code and last }
And add this class having main method. Then execute and see result.

class program {

public static void main(String[] a){
Emp obj = new Emp();

obj.display();
}
}

edit : more info:
https://www.digitalocean.com/community/tutorials/public-static-void-main-string-args-java-main-method

Answer 3

Excuse me can you explain more about "main method?