Javascript - Reduce array of arrays

Question

Array input: [["test","test"],["test2","test"],["test2","test2"],["test","test2"]]

Array output: ["test test","test2 test","test2 test2","test test2"]

I'm able to obtain this output with:

output = input.join("|").replace(/,/g," ").toString().split("|")

However, I don't really like this workaround because:

It seems unnatural
If one of the arrays contains a comma itself, it will be also removed
If one of the arrays contains a pipe itself, the split will be not as expected

How can I get the output without those handicaps?

#FP: a generic util var join = glue => arr => Array.prototype.join.call(Object(arr), glue); and it's usage arr.map( join(" ") ); works on anything that looks like an Array. — Thomas
– Thomas, Commented May 24, 2016 at 19:43

Oriol · Accepted Answer · 2016-05-24 19:16:32Z

10

Instead of joining the outer array, you can use map to join each inner array separately:

var arr = [["test","test"],["test2","test"],["test2","test2"],["test","test2"]];
var output = arr.map(subarr => subarr.join(' '));

answered May 24, 2016 at 19:16

Oriol

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1 Comment

It works perfect, thx. Thanks also for the map method. It looks really powerfull.