Filling an Array with a Given Value in Javascript
The Array.fill() method can be used to fill an array with a specific value, starting from a given index and ending upto another index.
Flatten Array Containing Arrays in JavaScript
Flattening an array refers to the process taking an input array, which may itself contain n-dimensional arrays as its elements, to a single array. This can be done in Javascript using the flat() method.
Format Number as Currency in Javascript
The Intl.NumberFormat object can be used to format a number as a currency using Javascript. Various options can be set to customize format of currency code, comma / decimal separators etc.
Knowing whether Promise is Completed (either Fulfilled or Rejected) with finally() Callback
The finally() callback can be used to know whether the Promise was settled. We don't care whether it was resolved or rejected.
Setting Default Values to Variables if null or undefined (using Nullish Coalescing Operator)
The nullish coalescing operator has been newly introduced in Javascript. This can be used to give default values if a variable is either null or undefined.
What Happens to setTimeout() / setInterval() Timers Running on Inactive Browser Tabs ?
Time delay for setTimeout() / setInterval() methods executing on inactive browser tabs are set to one second regardless of their value defined in code.
How to Disable Page Scrolling when Modal Dialog is Opened
When a fixed-position modal dialog is opened, scrollbars on the page can be removed by dynamically setting overflow:hidden CSS for the 〈body〉tag.
Disabling Pull-to-Refresh Feature on Mobile Browsers using CSS
Pull-to-refresh feature on mobile browsers that refreshes the page, can be disabled using the overflow-behaviour CSS property.
Synchronous / Asynchronous Image Decode using〈img decoding〉Attribute
The "decoding" attribute can be included for an 〈img〉tag to specify whether to decode the image in parallel or along with the rest of the page content.
Preventing Addition of New Properties to a Javascript Object with Object.seal()
The Object.seal() method seals an object. After an object gets sealed, no new properties can be added to it.
Preventing Changes to a Javascript Object with Object.freeze()
The Object.freeze() method can make an object or array immutable. No changes can be made to that object once it gets immutable.
Latest CSS Properties and APIs for Web Design in 2020 (VIDEO)
Many next generation CSS properties and APIs have been introduced in browsers lately. These can help in creation of user interfaces that were previously not possible or were difficult to achieve.
Hashbang Comments - The Third Way of Adding Comments in Javascript Code
Hashbang comments is the third type of syntax for adding comments to Javascript code. This comment can specify the Javascript interpreter that is to be used to execute the code within a script file or a module.
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
Preventing Autofilling the Password Field in HTML Forms
To prevent situations where we would not like the browser to autofill the password field in a form, the autocomplete=new-password attribute can be used.
Performance Tip : Learning to Think Beyond the Main Thread (VIDEO)
If Javascript code executed on the main thread could be offloaded to several Web Workers, then performance problem of a web application would be solved almost completely.
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.
Representing Edits to HTML Pages using〈ins〉&〈del〉Tags
Often there are edits made to documents. In HTML these changes can be highlighted using the 〈ins〉and 〈del〉 tags.