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!
![Designing for Simplicity]()
Before we get started, it's worth me spending a brief moment introducing myself to you. My name is Mark (or @integralist if Twitter happens to be your communication tool of choice) and I currently work for BBC News in London England as a principal engineer/tech...
![9 Mind-Blowing WebGL Demos]()
As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us. Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos. Another technology available...
![HTML5 Placeholder Styling with CSS]()
Last week I showed you how you could style selected text with CSS. I've searched for more interesting CSS style properties and found another: INPUT placeholder styling. Let me show you how to style placeholder text within INPUTelements with some unique CSS code.
The CSS
Firefox...
![MooTools 1.2 Image Protector: dwProtector]()
Image protection is a hot topic on the net these days, and why shouldn't it be? If you spent two hours designing an awesome graphic, would you want it ripped of in matter of seconds? Hell no! That's why I've created an image...
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.