Unique Array Values
When you look at any programming language, you see missing features that you find puzzling because the use case seems so common. One such case is retrieving unique values from an array with JavaScript. Years ago I mentioned an easy way of unique value management using objects instead of arrays, but that's not always an option and doesn't match every use case.
Want to retrieve a unique array of values from an array that may include duplicate values? You can use new JavaScript spread operator with Set to get an array of unique values:
var j = [...new Set([1, 2, 3, 3])]
>> [1, 2, 3]
Getting unique array values is another awesome usage of the spread operator. And don't forget you can merge object properties with the spread operator!
There's no better feeling than being able to remove a library to complete a task that should be native to the language. This trick brings us one step closer to that!
![Send Text Messages with PHP]()
Kids these days, I tell ya. All they care about is the technology. The video games. The bottled water. Oh, and the texting, always the texting. Back in my day, all we had was...OK, I had all of these things too. But I still don't get...
![Write Better JavaScript with Promises]()
You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll...
![JavaScript Canvas Image Conversion]()
At last week's Mozilla WebDev Offsite, we all spent half of the last day hacking on our future Mozilla Marketplace app. One mobile app that recently got a lot of attention was Instagram, which sold to Facebook for the bat shit crazy price of one...
![RealTime Stock Quotes with MooTools Request.Stocks and YQL]()
It goes without saying but MooTools' inheritance pattern allows for creation of small, simple classes that possess immense power. One example of that power is a class that inherits from Request, Request.JSON, and Request.JSONP: Request.Stocks. Created by Enrique Erne, this great MooTools class acts as...
If you’re forced to stay in EC5-land without the spread operator, you can use the pollyfillable
Array.from()Doesn’t seem to work for arrays of objects unless I’m missing something.
If your array is an object, you can use map function, to get the value in an array.
then you can run method like above.
Anybody using babel with this one should be cautious, this will result in an array with a single set element. Patrick Denny’s is the most predictable form.
Thanks David! Very helpful! :)