Array(3) // [empty × 3] Array(3).fill() // [undefined, undefined, undefined]
Array(3).fill('whatever') // ["whatever", "whatever", "whatever"] -----Original Message----- From: es-discuss <es-discuss-boun...@mozilla.org> On Behalf Of Bergi Sent: Monday, February 10, 2020 1:27 PM To: es-discuss@mozilla.org Subject: Re: Yet another attempt at typed JS data Hello! > Unfortunately, `Array.from({ length: 4 }, () => whatever)` produces a > holey array Does it? But really, if the performance difference betweeen HOLEY and PACKED arrays were large enough to be relevant[1], the engine programmers would certainly already have optimised all those trivial cases where an array is filled gradually to produce the more efficient representation. kind regards, Bergi [1]: it probably isn't: https://stackoverflow.com/questions/54481918/#comment95848513_54485509 _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss