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Java Class class isInstance() method with example

Class class isInstance() method: Here, we are going to learn about the isInstance() method of Class class with its syntax and example.
Submitted by Preeti Jain, on November 02, 2019

Class class isInstance() method

• isInstance() method is available in java.lang package.
• isInstance() method is used to check whether the given object is an instance with the object denoted by this Class or not.
• isInstance() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• isInstance() method does not throw an exception at the time of checking the given object is assignment compatible with other objects or not.

Syntax:

    public boolean isInstance(Object o);

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of this method is boolean, it returns a boolean value based on the following cases,

• It returns true, when the given Object is instance of this Class.
• It returns false, when the given Object is not instance of this Class.

Example:

// Java program to demonstrate the example 
// of boolean isInstance(Object o) method of Class

public class IsInstanceOfClass {
    public static void main(String[] args) {
        // Create and Return String class
        String str = new String();
        Class cl1 = str.getClass();

        // Create and Return IsInstanceOfClass class
        IsInstanceOfClass in = new IsInstanceOfClass();
        Class cl2 = in .getClass();

        // Create String and Integer class instance
        String s = new String();
        Integer i = new Integer(10);

        // We are checking instance of which classes
        boolean b1 = cl1.isInstance(s);
        boolean b2 = cl2.isInstance(i);

        System.out.print("Is s is an instance of" + " ");
        System.out.println(cl1.getSimpleName() + ": " + b1);

        System.out.print("Is i is an instance of" + " ");
        System.out.println(cl2.getSimpleName() + ": " + b2);
    }
}

Output

Is s is an instance of String: true
Is i is an instance of IsInstanceOfClass: false