What is instanceof operator ?

Question

hat is the meaning of instanceof operator ? and Why it is used in OOPS programming ? and How to implement in program ?

Priyanka K S · Answer

instanceof is a binary operator used to test if an object is of a given type. The result of the operation is either true or false. It's also known as type comparison operator because it compares the instance with type. Before casting an unknown object, the instanceof check should always be used. true – if variable is instance of specified class, it’s parent class or implement specified interface or it’s parent interface false – if variable is not instance of the class or implement the interface; or variable is null if (obj is FooObject) { ((FooObject)obj).Foo(); } Is equivalent to if (obj instanceof FooObject) { ((FooObject)obj).foo(); }

Daril · Answer

It is used to test if an object/instance is a subtype of a given type. It is a binary operator and returns a boolean value(true/false) you can use it to find out if an object is an instance of a class. class AAA{ public static void main(String args[]){ AAA a=new AAA(); System.out.println(a instanceof AAA); } } The output will be "true". a subcalss's object is also a type of parent calss. Example if bee extends insects then object of bee can be referred by both the bee or insects calss.

What is instanceof operator ?

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