On Wed, Dec 12, 2012 at 6:08 PM, Rick Waldron <[email protected]>wrote:
> > > > On Wed, Dec 12, 2012 at 1:59 AM, Axel Rauschmayer <[email protected]>wrote: > >> I would still love to have something like that in ES6 (loosely similar to >> String.prototype.repeat). Once you have that, you can e.g. use >> Array.prototype.map to do more things. >> >> Two possibilities: >> - Array.repeat(undefined, 3) -> [ undefined, undefined, undefined ] >> - [ undefined ].repeat(3) -> [ undefined, undefined, undefined ] >> >> The same array could be created like this, but that seems too much work >> for a relatively common operation. >> >> 'x'.repeat(3).split('').map(=> undefined) >> > > Array Comprehensions! > > This is probably wrong, so treat it more like an idea and less like a > matter of fact: > > [ undefined for x of new Array(3) ].map( v => ... ); > > [ undefined for x of [0,0,0] ].map( v => ... ); > This should work, too (at least it works in Firefox, if you use a normal function): var powersOfTwo = [ ...Array(8) ].map( (v, i) => 1 << i ) Cheers, Jussi > Rick > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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