I was going to say... indexOf with a callback is the best thing since sliced bread.
On Mar 3, 2013, at 5:26 PM, Rick Waldron <[email protected]> wrote: > > > > On Sun, Mar 3, 2013 at 5:33 PM, Brendan Eich <[email protected]> wrote: >> Bjoern Hoehrmann wrote: >>> * David Bruant wrote: >>>> I've found myself multiple times in a situation where I needed the index >>>> of the first element responding to some conditions. I solved it the >>>> following way: >>>> >>>> var index; >>>> array.some(function(e, i){ >>>> if(someCondition(e)){ >>>> index = i; >>>> return false; >>>> } >>>> >>>> return true; >>>> }) >>> >>> It's usually a bad idea to trigger side-effects from such callbacks. The >>> proper solution here would be having a suitable method available, like >>> >>> var index = array.findIndex(someCondition); >>> >>> as it is called in Haskell and C#. >> >> Hi Bjoern, findIndex is indeed a missing Array generic. I'll see if we can >> get it on the agenda for the next TC39 meeting (coming up quickly, >> mid-March). Thanks, > > Despite my previous message with a solution that relied on array.reduce(...), > the benefit of stopping the iteration (once the predicate returns true) is > objectively compelling. > > Rick > >> >> /be > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss
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