Aliases with JavaScript Destructuring
Destructuring in JavaScript has totally changed the way JavaScript is written these days; code is more concise to write but but, from a visual standpoint, the syntax of the language has changed so much. Any good developer knows, however, that change is the constant we live in.
The basic idea behind destructuring in object literals is as follows:
const obj = { x: 1 };
// Grabs obj.x as { x }
const { x } = obj;
There are cases where you want the destructured variable to have a different name than the property name; in that case, you'll use a : newName to specify a name for the variable:
// Grabs obj.x as as { otherName }
const { x: otherName } = obj;
The syntax for specifying an alternate destructured name for an object property is simple and needed. Destructuring had the capability to confuse developers, especially array destructuring and function argument destructuring, but this alias syntax is a simple trick to keep in your locker!
![6 Things You Didn’t Know About Firefox OS]()
Firefox OS is all over the tech news and for good reason: Mozilla's finally given web developers the platform that they need to create apps the way they've been creating them for years -- with CSS, HTML, and JavaScript. Firefox OS has been rapidly improving...
![Vibration API]()
Many of the new APIs provided to us by browser vendors are more targeted toward the mobile user than the desktop user. One of those simple APIs the Vibration API. The Vibration API allows developers to direct the device, using JavaScript, to vibrate in...
![Downloadify: Client-Side File Generation Using JavaScript and Flash]()
The following tools is in its very beta stages and works intermittently. Its so damn useful that I had to show it off now though!
I recently stumbled upon Downloadify, a client-side file generation tool based on JavaScript and Flash ActionScript code. A...
![CSS Counters]()
Counters. They were a staple of the Geocities / early web scene that many of us "older" developers grew up with; a feature then, the butt of web jokes now. CSS has implemented its own type of counter, one more sane and straight-forward than the ole...
Always have to check your site first to see any updates. Love it david. That’s where good developers stand out. Always adapting to new changes. Just trying to get hang of destructing as i’m not the smartest one in the room.
Hello. I’m using an alias for my destructed object property. How can I handle the property when it’s undefined?
Thanks.
I was looking for something like this. I wonder why the proposal for this feature didn’t follow the syntax of import statements.
Example:
const { x as otherName } = obj;this is the typescript syntax
I don’t know why people call it an “alias”. If it were an alias, changing the variable would change the object property. E.g.
let obj = { x: 1 } let { x: x_notalias } = obj x_notalias = 2 // 2 obj // { x: 1 }I think the only time you can have an alias in JavaScript is with reference types.
let obj = { x: 1 } let obj_alias = obj obj_alias.x = 2 obj // { x: 2 }When destructuring we use the word “alias” to refer to a differently named variable with the same value, rather than a different name that should reference the same variable.