Which equals operator (== vs ===) should be used in JavaScript ...
Dec 11, 2008 · I'm using JSLint to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing …
What does the !! (double exclamation mark) operator do in JavaScript ...
Novice JavaScript developers need to know that the "not not" operator is using implicitly the original loose comparison method instead of the exact === or !== operators and also the hidden cast …
javascript - When should I use ?? (nullish coalescing) vs || (logical ...
Related to Is there a "null coalescing" operator in JavaScript? - JavaScript now has a ?? operator which I see in use more frequently. Previously most JavaScript code used ||. let userAge =
Why would a JavaScript variable start with a dollar sign?
A valid JavaScript identifier shuold must start with a letter, underscore (_), or dollar sign ($); subsequent characters can also be digits (0-9). Because JavaScript is case sensitive, letters include the …
What is the correct way to check for string equality in JavaScript ...
In all other cases, you're safe to use ==. Not only is it safe, but in many cases it simplifies your code in a way that improves readability. I still recommend Crockford's talk for developers who don't want to …
javascript - Get the last item in an array - Stack Overflow
var linkElement = document.getElementById("BackButton"); var loc_array = document.location.href.split('/'); var newT = …
JavaScript hide/show element - Stack Overflow
Learn how to use JavaScript to hide or show elements on a webpage effectively.
Most efficient method to groupby on an array of objects
What is the most efficient way to groupby objects in an array? For example, given this array of objects:
javascript - How can I check if a string is a valid number? - Stack ...
In JavaScript, it's not always as straightforward as it should be to reliably check if a value is a number. It's common for devs to use +, -, or Number () to cast a string value to a number (for example, when …
javascript - Wait 5 seconds before executing next line - Stack Overflow
This function below doesn’t work like I want it to; being a JS novice I can’t figure out why. I need it to wait 5 seconds before checking whether the newState is -1. Currently, it doesn’t wait, i...