Why do I need underscores in swift?

Question

Here it says, \"Note: the _ means “I don’t care about that value”\", but coming from JavaScript, I don\'t understand what that means.

The only way I can

Answer 1

func divmod(_ a: Int, _ b:Int) -> (Int, Int) {
    return (a / b, a % b)
}

func divmod(a: Int, b:Int) -> (Int, Int) {
    return (a / b, a % b)
}

The _ is a placeholder for the parameter name. In your example, you call them differently, in the second function, you need to write the parameter name a: 1.

Swift's function name convention is funcName(param1:param2:), and it needs the _ as a placeholder to create the name of the function.

In the first name, the name is

divmod(_:_:)

Whereas the second is

divmod(a:b:)