what to use about this im new in java languages

Question

public class Data

{

public static void main (String [] args)

{

double size = 125.83d;

short grade = 87;

double final_grade = grade;

int final_lenght = size;

System.out.println("data is :" +sum);

}

}

Answer 1

This is used for a non-static class.
So first you need to create a class.
The main function is static so it doesn't do that automatically.
So create an object of Main type (or some other class from a file with the same name):

public class Main {     public static void main(String[] args) {         System.out.println("Hello World 1");         Main example = new Main("Hello World 2");         example.println();     }     private String text;     public Main(String text) {         this.text = text; // copy the input argument to the class member     }     public void println() {         System.out.println(this.text); // print the class member     } }