to distinguish between them, always use the type-strict comparison operator (===).After reading your clarification, @Ates Goral's answer provides how to perform the same operation you're doing in C# in JavaScript. But what if I told you we could do the same exact thing in just one line of code?

The ternary operator is right-associative, which means it can be "chained" in the following way, similar to an Get the latest and greatest from MDN delivered straight to your inbox.The newsletter is offered in English only at the moment. If condition is any of these, the result of the conditional expression will be the result of executing the expression exprIfFalse.
Where developers & technologists share private knowledge with coworkersProgramming & related technical career opportunitiesNote from January 2020: Nullish coalescing operator is available natively in Firefox 72 but optional chaining operator is still not.Strings like "false", "undefined", "null", "0", "empty", "deleted" are all true since they are non-empty strings.This needs to be clarified. "" Parent: layout.ternary.domain Type: array Default: [0, 1] Sets the vertical domain of this ternary subplot (in plot fraction). values as usable (eg. '' like this:if such case, the type of your variable is 'undefined'.notice that if you use the type-converting comparison operator (==), JavaScript will act equally for both of these empty-values.

The ternary operator is right-associative, which means it can be "chained" in the following way, similar to an Get the latest and greatest from MDN delivered straight to your inbox.The newsletter is offered in English only at the moment. If you haven’t already created an account, you will be prompted to do so after signing in. If this is true, they’re old enough to drive and driver should say 'Yes'.

You should comment under vaughan's answer instead. (+1)I think I might actually prefer defining a function that returns Best practices - treat arguments as array-like, take advantage of NaN !== NaN (@impinball, your suggested edit doesn't work, it returns NaN instead of 0 (zero) from my test case. Passing in the exising value as the 2nd choice in the ternary guards against this: alert(null || '') still alerts an empty string, and I think I actually like that alert('' || 'blah') alerts blah rather than an empty string - good to know though! is not null but is consider falsey.

Earlier, when one wanted to assign a default value to a variable, a common pattern was to use the logical OR operator (||): However, due to || being a boolean logical operator, the left hand-side operand was coerced to a boolean for the evaluation and any falsy value (0, '', NaN, null, undefined) was not returned. Become a faster developer and check out this guide to shorthand JavaScript coding techniques, with longhand versions for comparison. In other words, By using our site, you acknowledge that you have read and understand our

returns its right-hand side operand when its left-hand side operand is We could use an ifstatement to accomplish this: But what if I told you we could do … This mean several things: A variable being set to null means it contains data, the data being a reference to the null object. If you'd like to contribute to the interactive examples project, please clone The compatibility table on this page is generated from structured data. 1. To do this, we must separate the operations with a comma. It behaves like the C# ?? This is not the same as the variable not being declared.The actual difference between a variable being declared or not: alert(window.test)/*undefined*/; alert("test" in window)/*false*/; window.test = undefined; alert(window.test)/*undefined*/; alert("test" in window)/*true*/; for (var p in window) {/*p can be "test"*/}One things that bugged me about that article (and Jash) is, an undefined window.hello property being evaluated to null for some reason.