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.