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!
![5 HTML5 APIs You Didn’t Know Existed]()
When you say or read "HTML5", you half expect exotic dancers and unicorns to walk into the room to the tune of "I'm Sexy and I Know It." Can you blame us though? We watched the fundamental APIs stagnate for so long that a basic feature...
![Interview with a Pornhub Web Developer]()
Regardless of your stance on pornography, it would be impossible to deny the massive impact the adult website industry has had on pushing the web forward. From pushing the browser's video limits to pushing ads through WebSocket so ad blockers don't detect them, you have...
![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...
![HTML5 download Attribute]()
I tend to get caught up on the JavaScript side of the HTML5 revolution, and can you blame me? HTML5 gives us awesome "big" stuff like WebSockets, Web Workers, History, Storage and little helpers like the Element classList collection. There are, however, smaller features in...
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! :)