Loading CSS Stylesheet on Demand Through Its disabled Attribute
A stylesheet can include the disabled attribute in its markup to prevent it from being downloaded on page load. Later when the stylesheet needs to loaded on demand, its disabled attribute can be removed with Javascript.
Numeric Separators in Javascript to Improve Readability of Large Numbers
Numeric separators can be used to improve readability of large numbers. For example the number 111111111111111111111111, which is difficult to read, can be alternately written as 111_111_111_111_111_111_111_111
Detecting Change in Playing Subtitles Text for 〈video〉Element
Sometimes we would like to detect when the subtitles change in the playing video. This can be done by listening to the cuechange event on the 〈track〉element.
Preserving Context of this Inside AJAX Response Callbacks in jQuery
It is very common to access current this context inside jQuery AJAX's response callbacks (success or error). This tutorial describes 3 ways of doing this.
Checking whether Page is Opened / Active in Browser Tab
The Page Visibility API can be used to check whether a browser tab is active or not, i.e. if the page is in view or hidden from view.
How to Load Google Fonts with JavaScript
Google Fonts can be loaded through Javascript using the Web Font Loader Library. Events are also triggered when fonts are being loaded, or when they are rendered.
Converting Timestamp to Date & Time in Javascript
A UNIX timestamp can be converted to the required date and time formats in Javascript using the Date() object and its methods.
Looping through querySelectorAll() with Javascript
List of nodes returned by querySelectorAll() can be looped through using the forEach() method of the returned NodeList object.
Differences between 〈script type=module〉and〈script〉
Whenever a Javascript module needs to be applied to HTML, we need to do it within a 〈script type=module〉 tag. However there are some difference in Javascript execution in this tag vs a normal 〈script〉tag.
Loop through〈select〉Options with Javascript
Options of a dropdown 〈select〉element can be looped over its options property. This property gives a list of all 〈option〉elements inside it.
What is script type=module ?
A script tag having type=module attribute specifies that it to be considered as a Javascript module. It may be importing other Javascript module(s) inside it and becomes a top-level module for the imported modules.
How to Prevent Disqus Comments System from Slowing Page Speed & Performance
Loading Disqus' script files and comments on page load can lower down speed and performance of the page, specially in mobiles. A solution would be to use an Intersection Observer to lazily load Disqus.
How to Detect Number of Processor Cores with Javascript
The number of available logical processor cores in the device can be found with the navigator.hardwareConcurrency Javascript property. This number can be useful in knowing how many Web Workers can be executed in parallel.
Javascript KV Storage Introduction Tutorial
KV Storage API is an asynchronous way to save data in the browser using Javascript Promises. Its asynchronous nature guarantees that the performance of the application is not impacted.
How to write Immediately-invoked / Anonymous Async Functions (IIFE)
An anonymous async function can be defined using the Immediately-invoked Function Expression pattern for asynchronous functions.
How to Convert Array to a String in Javascript
A Javascript array can be converted to a string by using the join() method to join elements of the array separated by a given character or string.
How to Create QR Codes in JavaScript
QR codes have become really popular these days. In web pages QR Codes can be generated using the QRCode.js Javascript library.
How to Prevent Form Validation on Page Load & While Typing on Input Field (HTML Constraint Validation API)
The Constraint Validation API validates HTML forms on page load, and while typing on an input field. This seemingly confusing behavoiur to the user can be modified using a bit of CSS and Javascript.
How to Remove Duplicates from an Array using the Set Datatype
Duplicate elements can be removed from a Javascript array using the Set data type. A Set object can be created from the array, and then the Set can be converted back to an array.
How to Assign Default Values to Function Parameters in JavaScript
Function parameters can be initialized with a default value in the parameter list itself using ES6 default parameters.