Is there an elegant way of concatenating an array of arrays?

Question

so i have an array, containing arrays inside:

var arr = [
    [1,2,3,4,5],
    [6,7],
    [8,9,0]
];

What's the most elegant way to extract

[1,2,3,4,5,6,7,8,9,0]

I can make it like:

var final = [];
params.forEach(function(bulk){
    final = final.concat(bulk);
});

but was looking for something more elegant / pretty

possible duplicate of [Merge/flatten an Array of Arrays in JavaScript?](http://stackoverflow.com/questions/10865025/merge-flatten-an-array-of-arrays-in-javascript) — Etheryte, Jan 18 '15 at 19:55

score 1 · Answer 1 · answered Jan 18 '15 at 19:54

1

How about:

Array.prototype.concat.apply([], [
    [1,2,3,4,5],
    [6,7],
    [8,9,0]
]);

// [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]

Note that you can further reduce it to [].concat.apply but might have a cost of creation of an extra (empty) array (I guess this is browser implementation-dependent).

answered Jan 18 '15 at 19:54

Oleg

8,818
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i have no idea why someone downvoted you. this is exactly what i'm looking for, thanks – André Alçada Padez Jan 18 '15 at 19:57

Oleksandr T. · Answer 2 · 2015-01-18T20:01:05.317

1

Try this

console.log([].concat.apply([], arr));

If array has only numbers you also can use this

arr.toString().split(',').map(Number);

Example

edited Jan 18 '15 at 20:01

answered Jan 18 '15 at 19:54

Oleksandr T.

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Is there an elegant way of concatenating an array of arrays?

2 Answers2