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:
Which equals operator (== vs ===) should be used in JavaScript ...
Sur votre iPhone et votre iPad JavaScript est activé par défaut pour les iPhone et les iPad. Activer JavaScript dans d'autres navigateurs Si vous utilisez un navigateur compatible autre que Chrome, consultez sa page d'assistance pour découvrir comment activer JavaScript. Si vous ne savez pas si votre navigateur est compatible avec JavaScript, reportez-vous à sa page d'assistance. Suivez les instructions spécifiques à votre navigateur : Microsoft Edge Mozilla Firefox Apple Safari Opera ...
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.
What does the !! (double exclamation mark) operator do in JavaScript ...
27 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.
JavaScript uses short-circuit evaluation for logical operators || and &&. However, it's different from other languages in that it returns the result of the last value that halted the execution, instead of a true or false value. The following values are considered falsy in JavaScript: false null "" (empty string) 0 Nan undefined Ignoring the operator precedence rules, and keeping things simple, the following examples show which value halted the evaluation, and gets returned as a result.