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iOS Swift 2.0 Functions Function Parameters Named Parameters

Manish Giri
Manish Giri
16,266 Points

Error on omitting the local parameter name for first argument

While watching this lecture, I wrote this code -

func concatenateStrings(a: String, b: String) -> String {
    return a + b

concatenateStrings("Hello", b: "Worlds")

But I got an error -

Missing argument label 'a:' in call

Why is this so? My Xcode is ver 8.0, which (I think) uses Swift 3. Has the rule of omitting local parameter name for first argument changed?

1 Answer

David Lin
David Lin
35,864 Points

Yes, Swift 3 requires explicitly labelling all parameters in function calls, including the first.