Consider the following code: function Parent() {} Parent.prototype.display = function() { console.log(‘Parent’); } function Child() {} Child.prototype = Object.create(Parent.prototype); Child.prototype.constructor = Child; Child.prototype.display = function() { console.log(‘Child’); } var c = new Child(); c.display(); // ‘Child’ In the above code, the final line will print ‘Child’ because c is an object of ‘Child’. Now, if… Continue reading Accessing parent prototype functions from Child

An abstract class is a ‘class’ that is used just for inheritance. We should not be creating objects directly from abstract classes. Here is the code: function Car(name) { if(this.constructor === Car) { throw ‘Cannot instantiate abstract class’; } this.name = name; } function i12() { Car.call(this, ‘i12′); } The key here is the ‘constructor’… Continue reading Creating abstract class in Javascript

The following code will show you how to create a function ‘revocable’ that will be used to grant/revoke access to other functions. The function that will be tested here is the add function to add 2 numbers. But the ‘revocable’ function is good enough to work for other functions as well. function add (x, y)… Continue reading How to create a revocable function to grant/revoke access to any other function?

Here is the JQuery code to highlight all occurrences of a given text in a container: $(“.container:contains(‘Google’)”).html(function(_, html) { return html.replace(/(Google)/g, ‘<span style=”background-color: yellow;”>$1</span>’); }); The above block will change all occurences of the text ‘Methods’ within an element of class ‘container’ and make the background color of the text yellow by inserting a new… Continue reading Highlight all occurrences of text in a container

There are times when you are scratching your head wondering how on earth the value of ‘this’ got changed. For example, if you are within a function called from an object, ‘this’ may point to that object. However, when the function is set as an event listener to a button, ‘this’ will be the button… Continue reading Hard binding ‘this’ in your code