) 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:

Jun 7, 2011 · It's a little hard to google when all you have are symbols ;) The terms to use are "JavaScript conditional operator". If you see any more funny symbols in JavaScript, you should try looking up JavaScript's operators first: Mozilla Developer Center's list of operators. The one exception you're likely to encounter is the $ symbol.

The exception for TypeScript? If myObject was an any, you're back in JavaScript's Wild West and can return it without !!, even if your return type is a Boolean. Keep in mind that these are JSX and TypeScript conventions, not ones inherent to JavaScript. But if you see strange 0s in your rendered JSX, think loose falsy management.

Dec 11, 2008 · JavaScript has two sets of equality operators: === and !==, and their evil twins == and !=. The good ones work the way you would expect. The good ones work the way you would expect. If the two operands are of the same type and have the same value, then === produces true and !== produces false .

Mar 29, 2022 · "Using the dollar sign is not very common in JavaScript, but professional programmers often use it as an alias for the main function in a JavaScript library. In the JavaScript library jQuery, for instance, the main function $ is used to select HTML elements. In jQuery $("p"); means "select all p elements". "

This operator is almost never used in JavaScript. Other programming languages (like C and Java) use it for performance reasons or to work with binary data. In JavaScript, it has questionable performance, and we rarely work with binary data. This operator expects two numbers and returns a number. In case they are not numbers, they are cast to ...

Mar 7, 2016 · I haven't seen anything here or on MDN. I'm sure I'm just missing something. There's got to be some documentation on this somewhere.

That is, JavaScript "short-circuits" the evaluation of Boolean operators and will return the value associated with either the first non-false variable value or whatever the last variable contains. See Anurag's explanation of those values that will evaluate to false.

Jan 11, 2023 · In JavaScript, if you're looking for A or B, but not both, you'll need to do something similar to:

May 25, 2018 · $ is simply a valid JavaScript identifier. JavaScript allows upper- and lower-case letters (in a wide variety of scripts, not just English), numbers (but not at the first character), $, _, and others.¹. Prototype, jQuery, and most javascript libraries …