Comma usage in swift - 


@ibaction func selectedgame(segue:uistoryboardsegue) {   if let gamepickerviewcontroller = segue.sourceviewcontroller as? gamepickerviewcontroller,     selectedgame = gamepickerviewcontroller.selectedgame {     detaillabel.text = selectedgame     game = selectedgame   } }

hi all, i'm following tutorial learn swift. yesterday found part of code can not find way understand means thatcomma means. can u pls explain me?

the comma used combine multiple optional bindings 1 statement avoid unnecessary nesting.

from swift 1.2,the if let construct can unwrap multiple optionals @ once, include intervening boolean conditions. lets express conditional control flow without unnecessary nesting.more details

for example:

var foo: int! var bar: string!  // swift 1.2  if let foo = foo,bar = bar {     // foo & bar have values. } else {  }  // before swift 1.2  if let foo = foo {     // nesting     if let bar = bar {         // foo & bar have value.     } }

xcode6.3 , above support swift1.2.


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