JavaScript : instanceof Operator
Description
The instanceof operator is used to check the type of an object at run time. The instanceof operator returns a boolean value that indicates if an object is an instance of a particular class.
Syntax
var result = objectName instanceof objectType
Parameters
objectName : Name of the Object.
objectType : The type of the object.
Example :
The following web document shows how the instanceof operator is used.
HTML Code
<!doctype html><head> <meta charset="utf-8"> <title>JavaScript instanceof operator example</title> <meta name="description" content="This document contains an example of JavaScript instanceof operator"/> </head> <body> <script src="javascript-instanceof-operator-example1.js"></script> </body> </html>
JS Code
var string1 = "w3resource"; //Declaring string object
var date1 = new Date(); //Declaring Date object
if (string1 instanceof String)
{
var newParagraph = document.createElement("p");
var newText = document.createTextNode('The type of string1 object is String');
newParagraph.appendChild(newText);
document.body.appendChild(newParagraph);
}
if (date1 instanceof Date)
{
var newParagraph1 = document.createElement("p");
var newText1 = document.createTextNode('The type of date1 object is Date');
newParagraph1.appendChild(newText1);
document.body.appendChild(newParagraph1);
}
View the example in the browser
