Global variables in Java

Question

How do you define Global variables in Java ?

Answer 1

Going by the concept, global variables, also known as instance variable are the class level variables,i.e., they are defined inside a class but outside methods. In order to make them available completely and use them directly provide the static keyword. So if i am writing a program for simple arithmetical operation and it requires a number pair then two instance variables are defined as such:

public class Add {
    static int a;
    static int b; 
    static int c;

    public static void main(String arg[]) {
        c=sum();
        System.out.println("Sum is: "+c); 
    }

    static int sum() {
       a=20;
       b=30;
       return a+b;   
    }
}

Output: Sum is: 50

Moreover using static keyword prior to the instance variables enable us not to specify datatypes for same variables again and again. Just write the variable directly.