instanceof Keyword in Java

This operator is used only for object reference variables. The operator checks whether the object is of a particular type (class type or interface type). instanceof operator is written as −

( Object reference variable ) instanceof (class/interface type)

If the object referred by the variable on the left side of the operator passes the IS-A check for the class/interface type on the right side, then the result will be true. Following is an example -

Example

 Live Demo

public class Test {
   public static void main(String args[]) {
      String name = "James"; // following will return true since name is type of String
      boolean result = name instanceof String;
      System.out.println( result );
   }
}

This will produce the following result −

Output

true

This operator will still return true if the object being compared is the assignment compatible with the type on the right. Following is one more example −

Example

 Live Demo

class Vehicle {}
public class Car extends Vehicle {
   public static void main(String args[]) {
      Vehicle a = new Car();
      boolean result = a instanceof Car;
      System.out.println( result );
   }
}

This will produce the following result −

Output

true