On Jul 4, 2012, at 10:31 AM, Hemanth H.M wrote: > var a,b = 1; sets b to 1 and a is undefined, this is more C like semantics. > > Where as a,b = b,a is more pythonis; Well then a,b=[1,2] should make sense ?
No, because all of these things have defined semantics. Let's say you replace var a,b=[1,2] with a,b=[1,2] That is still valid today. It evaluates as resolving "a" (which may or may not have side effects), and then assigning [1,2] to b. There is definitely code that does this in the variable declaration syntax, and knowing the web, probably code that does it in the non-var case. You can't use type checks either, because var a,b=c should not have different behaviour depending on the value of c. It has to be a distinct syntax, which is what we have been developing -- see http://wiki.ecmascript.org/doku.php?id=harmony:destructuring -- but that takes time. We have to resolve all of the potential issues in the syntax and semantics, then engines have to implement it. --Oliver > > /me also agrees to var[a,b] = foo; > > On Wed, Jul 4, 2012 at 10:47 PM, Oliver Hunt <[email protected]> wrote: > This doesn't do what you want as assignments in initialisers are optional. > This has the semantic effect of meaning that there is no difference between > > var a, b = foo; > > and > > var a; > var b = foo; > > We're working on introducing destructuring assignment so you'll be able to do > > var [a, b] = foo; > > which is what you want, but we're not quite there yet. > > --Oliver > > > On Jul 4, 2012, at 10:08 AM, Hemanth H.M wrote: > >> Hello Hackers, >> >> This might be silly, but let the code speak : >> >> var param1,param2 = window.location.search.replace('?','').split('&') >> undefined >> param1 >> undefined >> param2 >> ["foo=bar", "hello=world"] >> a=1 >> 1 >> b=2 >> 2 >> a,b=b,a >> 1 >> a >> 1 >> b >> 2 >> >> Why not param1 be equal to "foo=bar" and param2 be equal to "hello=world"? >> >> >> -- >> 'I am what I am because of who we all are' >> h3manth.com >> -- Hemanth HM >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss > > > > > -- > 'I am what I am because of who we all are' > h3manth.com > -- Hemanth HM
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