Remove Duplicate Numbers in 2D Array Javascript

Asked Jan 10 '20 at 03:29

Active Jan 10 '20 at 03:31

Viewed 311 times

I have a 2D array of number arrays like say

nonunique = [[1,2,3][2,3,4][1,5]];

I want a 1d array of all the unique keywords.

unique = [1,2,3,4,5];

Existing solutions aim at matching the entire arrays rather than just returning a 1d array of numbers. Any shortcuts to this in vanilla javascript?

I tried this reduce function from stackoverflow but it seems to filter some non-duplicate values too.

unique = nonunique.reduce((acc, val) => acc.concat(val.filter((e)=>acc.includes(val))));

It doesn't work properly and I can't figure out how to fix it. I also tried

unique = nonunique.filter(onlyUnique);

but filter(onlyUnique) doesn't seem to be available on firefox.

edited Jan 10 '20 at 03:31

asked Jan 10 '20 at 03:29

xmxmxmx

You should be using `!acc.includes(e)` (see [here](https://jsfiddle.net/vwbuph50/)) – Nick Parsons Jan 10 '20 at 03:37
Use sets. /thread – Crutch Master Jan 10 '20 at 03:55
Use this: `Array.from(new Set(nonunique.reduce(function (acc, val) { return acc.concat(val) }, [])));` – Vectrobyte Jan 10 '20 at 04:55

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