JavaScript Tutorial/Object Oriented/instanceof
Using instanceof operator to check the subclass created by Prototype Chaining
<source lang="javascript">
function SubClass() { } SubClass.prototype = new BaseClass(); SubClass.prototype.name = ""; SubClass.prototype.sayName = function () {
alert(this.name);
}; var objA = new BaseClass(); var objB = new SubClass(); var objB = new SubClass(); alert(objB instanceof BaseClass); //outputs "true"; alert(objB instanceof SubClass); //outputs "true"</source>