Just to make sure everything is clear, we’re going to write another closure example using two parameters.
This time our travel()
function will require a closure that specifies where someone is traveling to, and the speed they are going. This means we need to use (String, Int) -> String
for the parameter’s type:
func travel(action: (String, Int) -> String) {
print("I'm getting ready to go.")
let description = action("London", 60)
print(description)
print("I arrived!")
}
We’re going to call that using a trailing closure and shorthand closure parameter names. Because this accepts two parameters, we’ll be getting both $0
and $1
:
travel {
"I'm going to \($0) at \($1) miles per hour."
}
Some people prefer not to use shorthand parameter names like $0
because it can be confusing, and that’s OK – do whatever works best for you.
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