What is an instance variable in Java?

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My assignment is to make a program with an instance variable, a string, that should be input by the user. But I don’t even know what an instance variable is. What is an instance variable?

How do I create one? What does it do?


Instance variable is the variable declared inside a class, but outside a method: something like:

class IronMan {

    /** These are all instance variables **/
    public String realName;
    public String[] superPowers;
    public int age;

    /** Getters and setters here **/

Now this IronMan Class can be instantiated in another class to use these variables. Something like:

class Avengers {

    public static void main(String[] a) {
        IronMan ironman = new IronMan();
        ironman.realName = "Tony Stark";
        // or


This is how we use the instance variables. Shameless plug: This example was pulled from this free e-book here here.

Source: stackoverflow