“Functions are a first-class type” in swift?

Question

The little knowledge I have about first-class functions is that it supports passing functions as arguments and we can also return them as the values in another function ... I am very new in Swift programming language. Can anyone please elaborate it with an example?

Answer 1

A very simple example to demonstrate this behaviour:

func functionA() {
    println("Hello by functionA")
}

func executeFunction(function: () -> ()) {
    function()
}

executeFunction(functionA)