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!
![Regular Expressions for the Rest of Us]()
Sooner or later you'll run across a regular expression. With their cryptic syntax, confusing documentation and massive learning curve, most developers settle for copying and pasting them from StackOverflow and hoping they work. But what if you could decode regular expressions and harness their power? In...
![39 Shirts – Leaving Mozilla]()
In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...
![Create Keyboard Shortcuts with Mousetrap]()
Some of the finest parts of web apps are hidden in the little things. These "small details" can often add up to big, big gains. One of those small gains can be found in keyboard shortcuts. Awesome web apps like Gmail and GitHub use loads of...
![JavaScript Copy to Clipboard]()
"Copy to clipboard" functionality is something we all use dozens of times daily but the client side API around it has always been lacking; some older APIs and browser implementations required a scary "are you sure?"-style dialog before the content would be copied to clipboard -- not great for...
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! :)