InstanceOf Operators
Learn about the instanceOf operator with the help of an example in this lesson.
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These operators check whether an object is an instance of a class or a subclass. If a class implements an interface, that can also be checked.
Coding example: 53
Let us see the following example to understand how it works:
Java
/*You can use the instanceof operator to test if an object is an instance of a class,an instance of a subclass, or an instance of a class that implements a particular interface*/interface PlaceTheOrder{public void place();}class ParentClass implements PlaceTheOrder{public void place(){System.out.println("Placing the order.");}}class ChildClass extends ParentClass{}public class ExampleFiftyThree {public static void main(String[] args) {ParentClass parent = new ParentClass();ChildClass child = new ChildClass();/*The following two questions will have answers true*/System.out.println("Is parent instance of ParentClass? : " + (parent instanceof ParentClass));System.out.println("Is parent instance of interface PlaceTheOrder? : " + (parent instanceof PlaceTheOrder));//it is falseSystem.out.println("Is parent instance of ChildClass? : " + (parent instanceof ChildClass));/*The following answers will be true, because ChildClass is a subclass of ParentClass*/System.out.println("Is child instance of ChildClass? : " + (child instanceof ChildClass));System.out.println("Is child instance of ParentClass? : " + (child instanceof ParentClass));System.out.println("Is child instance of interface PlaceTheOrder? : " + (child instanceof PlaceTheOrder));}}
Code explanation
As you see in the above code, there are two classes and one interface. One is the parent class, and one is the child class. The ...