Blogs
In JavaScript, we have Equality (==) and Identity(===) operators for equality comparison between two values/operands. When first time we see Equality (==) and Identity (===) operators, then following questions arise in our mind. 1. What is difference between Equality (==) and Identity (===) ? 2. Is there a performance benefit with...
Many a times we get confused with scope in JavaScript, So here I am going to put some light on scope. There are two types of scope in JavaScript. First one is, function scope which is also called as local scope, and second one is global scope. Function Scope: In JavaScript, variables are defined with function scope instead of block...
MongoDB provides a rich set of aggregation. $group is one of them, with the help of $group, we can group documents (similar as group By in SQL). Lets understand by an example: Suppose we have following collection of blogs: [js] { userId:1, name:"Suroor", title:"AngularJS: Getting started with Directive", rating:3} { userId:2,...
Like other languages(Java, php), we do not need to set up any Apache HTTP server. With Node, things are a bit different, with Node.js, we not only implement our application, we also implement the whole HTTP server. In fact, our web application and its web server are basically the same. Lets create a basic Node HTTP server. First let's...
We are assuming that you have installed js2 in your system, in case if you have not installed js2, first install js2. First of all create a InheritanceTest.js2 file in scr directory with the content given below: [js] class Person { // Parent class var firstName; var lastName; function initialize(firstName, lastName)...
We are assuming that you have installed node.js in your system, in case if you have not installed node.js, first install node.js. To install js2 run the command given below: [bash] npm install js2 [/bash] Let’s create a simple Hello World project, but first let’s create a project directory structure: [bash] mkdir...
There are four patterns of invocation in JavaScript: 1. The method invocation pattern. 2. The function invocation pattern. 3. The constructor invocation pattern. 4. The apply invocation pattern. 1. The Method Invocation Pattern: When a function is stored as a property of an object, we call it a method. When a method is invoked,...
As we all know that groovy is a dynamic programming language, so we can add any method to any class at runtime. First, let’s see a small and simple example of metaProgamming given below, in which we are adding a method (isEvent) into an Integer class. [groovy] Integer.metaClass.isEven = { -> // only (->) sign indicates that...
In my current project, I tried to call a javascript function on onload event of body tag of gsp page: [html] ... [/html] But this onload event was not fired, because Grails picks the body tag from layout and not from the view. So I added the following line in body tag of my layout [html] ... [/html] In above example...