Or for that matter, similarly.... Array.fill(), which has the same signature, but an empty array as Array.prototype.fill.
-- Michael J. Ryan - http://tracker1.info On Tue, Mar 27, 2018 at 5:24 PM Michael J. Ryan <[email protected]> wrote: > How about something like... > > Array.prototype.fill = function(filler, times, flatten) { > var ret = [].concat(this); > var len = Number(times) || 0; > var (var i=0; i<len; i++) { > if (flatten && Array.isArray(filler)) { > ret.push.apply(ret, filler); > } else { > ret.push(filler); > } > } > return ret; > } > > [].fill(0, 3) // [0, 0, 0] > [].fill(['a', 'b'], 2) // [['a', 'b'], ['a', 'b']] > [].fill(['a', 'b'], 2, true) // ['a', 'b', 'a', 'b'] > > -- > Michael J. Ryan - http://tracker1.info > > > On Mon, Mar 26, 2018 at 12:02 PM Cyril Auburtin <[email protected]> > wrote: > >> > maybe fill with incrementing number? >> >> ```js >> Array.from({length: 6}, (_, i) => i) >> ``` >> >> > Are there use cases for filling with alternating values, as in `['x', >> 'y'].repeat(3)`? >> >> Not so many, but for example when working with flat matrices, >> `[0,0,255,1].repeat(len)` for generating quickly a uniform imageData >> >> But even with one item, I find `[x].repeat(n)` more explicit than the 2 >> other alternatiives >> >> It's somewhat close to array comprehensions (that I don't really miss >> though) >> >> >> 2018-03-26 15:27 GMT+02:00 Jerry Schulteis <[email protected]>: >> >>> Whatever the use cases might be, I like generators and spread for >>> filling an array with values, e.g.: >>> >>> ```js >>> function* repeat(n, ...values) { >>> for (let i = 0; i < n; ++i) { >>> yield* values; >>> } >>> } >>> >>> [...repeat(3, 'x', 'y')] >>> ``` >>> >>> >>> On Sunday, March 25, 2018, 3:41:10 PM CDT, Claude Pache < >>> [email protected]> wrote: >>> >>> >>> [...] >>> >>> For filling a new array with one value, `Array(n).fill('foo')` seems >>> reasonable to me. >>> >>> Are there use cases for filling with alternating values, as in `['x', >>> 'y'].repeat(3)`? >>> >>> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >
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