Idiom for “repeat n times”?

Question

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EDIT: The votes to close are wrong. The accepted answer in Repeat Character N Times is not applicable in general. E.g.:

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Answer 1

Maybe the Array.from callback can be of use:

var result = Array.from(Array(3), Math.random);

console.log(result);

There is a slight advantage here over using map: map already needs an array with all the entries (maybe created with fill or the spread syntax), to then create the final array from that. So in total a map solution will create n entries twice. Array.from does not need an array with entries, just an object with a length property will do, and Array(3) is providing that.

So depending on your preferences, the above can also be done like this:

var result = Array.from({length:3}, Math.random);

console.log(result);

Finally, if you would create a repeat function for this, you can name the argument length and use the ES6 short notation for object literals:

const repeat = (length, cb) => Array.from({length}, cb);

const result = repeat(3, Math.random);
console.log(result);