Types of Variables

What are the Types of Variables?

Below are Types of variables available in Java:

1. Instance Variable
2. Static (or) Class Variable
3. Local Variable

Instance Variable:

• It is a variable that will be declared outside of any method, constructor, or block in a class.
• While declaring it should not use a static modifier.
• The instance variable can be accessed by using an object.

Static Variable:

• It is also known as Class Variable.
• It is a variable that will be declared using a static modifier outside of any method, constructor, or block in a class.
• A static variable can be directly accessed by using className (no need to create an object)
• The default value of the Integer static variable is Zero and for String static variable is null.

Local Variable:

• It is a variable that will be declared within a method, constructor, or block in a class.
• Scope of a local variable will be defined to its block, method or constructor
• final is the only modifier that can be applied to the local variable.
• A local variable must be initialized before they can be used

Types of Variables in Java

Demo on Types of Variables in Java:

public class TypesOfVariables {

    //Instance Variable

    int instanceVar;

    //Static Variable

    static String staticVar;
    static int j;

    public void method1() {
        final int a = 100; //local variable

        int b = 20;
        System.out.println(a);
    }

    public static void main(String args[]) {
        int a = 1001;//local variable 

       TypesOfVariables tov = new TypesOfVariables();
        System.out.println("Value of Instance variable=" + tov.instanceVar);
        System.out.println("Value of static variable=" + tov.staticVar);
        System.out.println("Value of static variable using class name =" + TypesOfVariables.staticVar);
        System.out.println("Value of static variable using class name =" + TypesOfVariables.j);
        tov.method1();
        System.out.println("Value of local variable=" + a);
    }
}

Output:

Types of Variables

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