Global variables in Java

Question

I am fairly new to Java, I wanted to know how can i define a global variable ?

Answer 1

To define a Global variable in java, the keyword static is used. Java actually doesn’t have the concept of Global variable, it is known as class variable ( static field ). These are the variables that can be used by the entire class.

Example -

public class Library {

          private String userName ; // instance variable, specific to a Library

          private static int userId ; // class variable

          // constructer used to initialise a Student object.

         public Library(String userName) {

                   this.userName = userName ;

         }

        public static incrementuserId( ) {

                   userId++;

}

}

Answer 2

To define the Global Variable, you can just use the static Keyword like this:

public class Example {

    public static int a;

    public static int b;

}

Now, you can access variable a and b from anywhere by calling like this:

Example.a;

Example.b;

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