RequireJS Interview Questions for freshers experienced :-
1. What is RequireJs?
RequireJs is a open source JavaScript library which is used to maintain dependencies between JavaScript files and modular programming.
2. What are the features of RequireJs?
Following are the key feature of RequireJs:
- It maintains dependency between JavaScript and programming code.
- It improves the speed of and quality of code.
- It also supports jQuerry without any conflict.
- It reduces code complexity in large applications.
3. What is the project structure of RequireJs?
To set up our RequireJs project strucrure, we need to download the latest version of ReuireJs. After downloading, we require to include require.js file in our libs folder.
4. What is module in RequireJs?
Module is independent unit of program which make easy maintenance and reusability of code. In RequireJs we talk about JavaScript module.
5. What is data-main attribute?
The data-main attribute is a special attribute that require.js will check to start script loading. The data-main set to the base URL for all the scripts.
<script src=”scripts/require.js” data-main=”scripts/app.js”></script>
6. What is AMD module?
AMD stands for Asynchronous Module Definition. This specifies a mechanism for defining modules and their dependencies in such a way that they can be loaded asynchronously and in the right order.
7. How to use RequireJs with Node? Or dose RequireJs support Node?
We use Node with RequireJs by using Node adapter. RequireJs load only those modules of Node which are on the local disk.
Node adapter can install by two different ways:
- By using command: npm install requires.
- By downloading file:
* Downloading r.js file and keeping it in our project folder.
* Getting source from r.js repository or generate r.js through “node dist.js”.
8. How to use RequireJs with jQuery?
ReqireJs uses jQuery as another dependency. jQuery is named as ‘jquery’ all in lower case and register itself as the global variables “$” and “jQuery”.
require([‘jquery’], function($){ }
9. How to use RequireJs with Dojo?
Dojo is AMD (Asynchronous Module Definition) based module. Dojo is used with RequireJs by using Dojo loader APIs. Dojo loader includes two types of APIs.
- Asynchronous Module Definition (AMD) API.
- Legacy dojo API.
10. How to use RequireJs with CommonJs?
CommonJs are used with RequireJs by converting its module in RequireJs format. Conversion can be done through manual and by using conversion tool.
Manual conversion:
define(function(require, exports, module) {
//Put CommonJS module content here
});
Using conversion tool:
<a href=”https://github.com/requirejs/r.js”>r.js project</a>
tool is used, which is present built in r.js to convert CommonJs module.
node r.js -convert path/to/commonjs/modules/ path/to/output
11. What is the use of define() function in RequireJs?
The define() function is used to load and execute module. It takes two optional parameters (module id and an array of required module) and one required parameter.
define(“module_id”,[“module1”, “module2”], function(module1,module2) {
}
);
12. What is the use of require() in RequireJs?
The require() function is used to load required dependency without creation of module.
require([‘jquery’], function ($) {
});
13. What is the use of config() in RequireJs?
The config() function is used to configure the RequireJs runtime functionality.
If we want to change the default configuration of RequireJs with our own configuration, we need to use requirejs.config() function with configuration details.
require.config({
baseUrl: ‘scripts/app’,
paths: {
},
shim: {
}
});
14. What is the role of Optimizer or Optimize?
Optimize is a built process where the developed project is deployed to end user. While optimize we combines all scripts files and css files together and minify them.
15. What are the plugins in RequireJs?
RequireJs’s plugin is used to load various types of resources as dependencies. Following are the plugins available in RequireJs:
- text: This plugin handles loading text based resources like HTML.
- domReady: It load such resource which tries to interact DOM
- cs (CoffeeScript): It load files written in CoffeeScript.
- i18n : It load string bundle used in internationalization (i18n) made up of different language.