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Discussion on: Number.range; Stage-1 proposal

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miketalbot profile image
Mike Talbot • Edited

I'd suggest the best way to do range today would be:

    const range = (start, end)=>Array.from({length: end-start}, (__,i)=>start+i)

No need to double memory and processing by spreading the result into an array or making another one with map.

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hemanth profile image
hemanth.hm Author

Yup, that is covered in the many other ways of doing this link.

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emnudge profile image
EmNudge

For most purposes, an iterator is actually preferable. These can be created via generators, as mentioned in the article.
I wrote one in an older article of mine:
dev.to/emnudge/generating-arrays-i...

class Range {
  constructor(min, max, step = 1) {
    this.val = min;
    this.end = max;
    this.step = step;
  }

  * [Symbol.iterator]() {
    while (this.val <= this.end) {
      yield this.val;
      this.val += this.step;
    }
  }
}