Sunday, Nov 6, 2016 [Tweets] [Favorites]

Underscore Uses in Swift

Dmitri Pavlutin (via Natasha Murashev):

You can use _ to suppress the argument label every time its indication seems redundant.


let (_, sub, _, div) contains _ at first and third positions. This indicates that addition and multiplication results are insignificant.


The flight speed case .flight(let speed, _) omits the information about the altitude using an underscore _. Extracting the altitude in this case is simply not necessary.


Otherwise you can discard the result using an underscore […] Such way you let know the compiler that you ignore the returned value. And no warning is triggered in this case.


If you need to skip naming some closure parameters, just mark those with underscores.


Another common usage of the underscore is to iterate a code block a particular number of times, and ignore the iteration value.


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