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 =
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.
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.
What does $ {} (dollar sign and curly braces) mean in a string in JavaScript? Asked 9 years, 9 months ago Modified 1 year, 11 months ago Viewed 425k times
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 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.
& is bitwise AND 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 numbers. How does it work ...
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.
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 use the $ as the primary base object (or function).
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 characters "A" through "Z" (uppercase) and the characters "a" through "z" (lowercase).
