Array.prototype.contains

Greg Smith greg at bocoup.com
Tue Jan 3 06:46:20 PST 2012


I see Array.contains as a great idea. This is an operation I use constantly
when I write code and it'd be nice to have it be a first class Array
operation. Sure it's not so different than indexOf, but the semantics are
much more intuitive and it may very well be the more common operation.

-Greg

On Fri, Dec 30, 2011 at 6:29 PM, Rick Waldron <waldron.rick at gmail.com>wrote:

> That's what I figured - I guess I thinking of implementations that would
> be ES3 & 5 compat
>
> Thanks!
>
>
> On Fri, Dec 30, 2011 at 6:26 PM, Brendan Eich <brendan at mozilla.com> wrote:
>
>> Jason doesn't want a wrapper written in JS that depends on the current
>> value of this.indexOf, I think. That's enough reason for a built-in. This
>> is a no-brainer for ES6 IMHO.
>>
>> /be
>>
>> ----- Original Message -----
>> From: "Rick Waldron" <waldron.rick at gmail.com>
>> To: "Jason Orendorff" <jason.orendorff at gmail.com>
>> Cc: "es-discuss" <es-discuss at mozilla.org>
>> Sent: Friday, December 30, 2011 2:28:28 PM
>> Subject: Re: Array.prototype.contains
>>
>>
>>
>> On Fri, Dec 30, 2011 at 5:24 PM, Jason Orendorff <
>> jason.orendorff at gmail.com > wrote:
>>
>>
>>
>> On Fri, Dec 30, 2011 at 6:58 AM, Xavier MONTILLET
>> < xavierm02.net at gmail.com > wrote:
>> > http://wiki.ecmascript.org/doku.php?id=harmony:string_extras
>> > There is a proposal for String.prototype.contains so why can't I find
>> > one for Array.prototype.contains?
>>
>> No kidding. I need this method every time I write ECMAScript code.
>> What I want is like:
>>
>> Object.defineProperty(Array.prototype, "contains", {
>> configurable: true,
>> writable: true,
>> value: function contains(x) {
>> return this.indexOf(x) !== -1;
>> }
>> });
>>
>> except without the property lookup for indexOf.
>>
>>
>>
>> At this.indexOf ? Or the whole "this.indexOf(x) !== -1;" lookup? How else
>> could it work?
>>
>>
>> Rick
>>
>>
>>
>> -j
>>
>>
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>
>
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