The nullish coalescing operator (??) in JavaScript only considers null or undefined as "nullish" values. If the left-hand side is any other value, even falsy values like "" (empty string), 0, or false, it will not use the right-hand side:

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 idSele_UNVEHtype.value.

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 operation that is happening behind the scenes and I show it in the example I provide.

Jan 16, 2010 · Find solutions to close a browser tab using JavaScript on Stack Overflow. Explore methods and limitations for different browsers.

Mar 29, 2022 · Javascript does have types; and in any case, how is the dollar sign even related to that? It's just a character that happens to be a legal identifier in Javascript.

Mar 7, 2016 · What does $ {} (dollar sign and curly braces) mean in a string in JavaScript? Asked 9 years, 4 months ago Modified 1 year, 7 months ago Viewed 418k times

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...

Mar 2, 2010 · How to use OR condition in a JavaScript IF statement? Asked 15 years, 5 months ago Modified 2 years, 6 months ago Viewed 874k times

In JavaScript there are 7 primitive types: undefined, null, boolean, string, number, bigint and symbol. Everything else is an object. The primitive types boolean, string and number can be wrapped by their object counterparts. These objects are instances of the Boolean, String and Number constructors respectively.

As of JULY 2018, this has been implemented in almost all major browsers, if you need to support an older browser a polyfill is available. Edit: Note that this returns false if the item in the array is an object. This is because similar objects are two different objects in JavaScript.