JavaScript instanceof Operator

JavaScript is not object oriented programming but we can implements some concepts of the object oriented programming in JavaScript.

When we create a class in JavaScript and creates the object of it so we can also check at the run time that the particular object is the instance of the particular class or not.

It simply check the prototype in object’s prototype chain.

It return true if the object is of specific class otherwise return the false.

Syntax

object instanceof ClassName

Let’s we create the class in the JavaScript, It’s nothing new but we can create the class in JavaScript using the function keyword.

function Books() {

}

var b1 = new Books();

alert(b1 instanceof Books); // return the true

var strBooks = "JavaScriptHive";
var myString = new String();

alert(strBooks instanceof String); // returns the false
alert(myString instanceof String) //returns the true

see the typeof operator.

 

Happy Coding. 🙂