Found 6685 Articles for Javascript

What are the differences between JavaScript Primitive Data Types and Objects?

Johar Ali
Updated on 03-Jan-2020 09:58:13

179 Views

Before beginning with the difference, let’s learn what are Primitive Datatypes. Primitive defines immutable values and introduced recently by ECMAScript standard.JavaScript allows you to work with three primitive data types, Numbers, eg. 3, 310.20 etc.Strings of text e.g. "This text string" etc.Boolean e.g. true or false.JavaScript also defines two trivial data types, null and undefined, each of which defines only a single value. In addition to these primitive data types, JavaScript supports a composite data type known as the object.After datatypes, let us discuss about Objects:Objects In JavaScript, objects are considered a collection of properties. Identify properties using key values. It ... Read More

How to write inline JavaScript code in HTML page?

Rahul Sharma
Updated on 13-Jun-2020 07:08:11

576 Views

Inline JavaScript Code − If you are adding some JavaScript code in an HTML file without using the src tag then it is known as inline JavaScript code. That’s all you need to know.

What are the differences between inline JavaScript and External file?

Johar Ali
Updated on 13-Jun-2020 06:51:11

443 Views

The following are the difference between inline JavaScript and external file −External scriptsThe browser stores the external script once it is downloaded for the first time. If it is to be referenced again, then no additional download is needed.This reduces download time and size.The async and defer attributes have an effect. If these attributes are present the script will change the default behavior.Inline scriptsInline Scripts are executed immediately.It gets loaded instantly and there is no need to trigger another request.The async and defer attributes has no effect.Inline Scripts are more useful for server-side dynamic rendering.Read More

Is it better to have one big JavaScript file or multiple light files?

Amit Sharma
Updated on 13-Jun-2020 06:48:03

982 Views

To avoid multiple server requests, group your JavaScript files into one. Whatever you use for performance, try to minify JavaScript to improve the load time of the web page.If you are using single page application, then group all the scripts in a single file.If you are using multiple files, then minify all of your scripts and separate them into categories.example - Place JavaScript to be used in every page. This can be the core script of the file. - Place your plugins hereRest, add other scripts in a JavaScript file. It’s good to maintain it in different files.Read More

How page load time affects with JavaScript?

Ali
Ali
Updated on 03-Jan-2020 07:15:01

369 Views

Page load time gets affected with JavaScript files and code. If you are not optimizing JavaScript files then the page load time will increase, which shouldn’t happen. Minify the JavaScript code to decrease the page load time.Also, cache JavaScript file for better results. For better performance, use inline and external JavaScript properly. Try to use external JavaScript file if you want to add the same script in multiple pages.External scriptsThe browser stores the external script once it is downloaded for the first time. If it is to be referenced again, then no additional download is needed.This reduces download time and ... Read More

How to use the same JavaScript in multiple content pages?

Rahul Sharma
Updated on 13-Jun-2020 06:45:08

1K+ Views

To use the same JavaScript in more than one page, add the js code in an external JavaScript file. Let’s say the following demo.js is our external JavaScript file −function display() {    alert("Hello World!"); }Now add the external JavaScript file to the following HTML web page. In the same way, you can add it to multiple content page.                                          

How does the browser identify inline JavaScripts?

Johar Ali
Updated on 13-Jun-2020 06:44:28

283 Views

Let’s say the following line we have in our HTML −Here the browser identifies inline JavaScript by detecting onclick, even when tag wasn’t available.The following are some of the suggestions for using inline JavaScripts −You should consider inline script elements such as ...) if the script only to be used for a single page.Do not use event attributes such as onclick="...", and bind event handlers using JavaScript.Use external script elements such as ) for most scripts, especially if reused between pages.

What are the rules for JavaScript's automatic semicolon insertion (ASI)?

Amit Sharma
Updated on 13-Jun-2020 06:43:18

184 Views

JavaScript’s automatic semicolon insertion (ASI) is to insert missing semicolons. The following statements are affected by automatic semicolon insertion −empty statement var statement expression statement do-while statement continue statement break statement return statement  throw statementThe rules are in the following specification −When, as a Script or Module is parsed from left to right: A token is encountered that is not allowed by any production of the grammar, then a semicolon is automatically inserted before the offending token only if one or more of the following conditions becomes true −Offending token is }.Previous token is ) and the inserted semicolon would ... Read More

How to disable resizable property of textarea using JavaScript?

Rahul Sharma
Updated on 13-Jun-2020 06:39:07

155 Views

To disable resizable property, use CSS style −textarea {    resize: none; }To disable specific textarea with different attribute values, try the following. Let’s say the attribute is set to “demo” −textarea[name=demo] {    resize: none; }Let’s say the id attribute is “demo” −For the above,#demo {    resize: none; }

How to handle when JavaScript is turned off?

Johar Ali
Updated on 13-Jun-2020 06:37:30

78 Views

Nowadays, almost every web browser supports JavaScript. If it is turned off, you can use tag. To let users know about non-JavaScript web browsers, use the tag. The HTML tag is used to handle the browsers, which do recognize tag but do not support scripting. This tag is used to display an alternate text message.Example           HTML noscript Tag                                              Your browser does not support JavaScript!          

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