无法快速加载viewDidLoad()中的函数 [英] Unable to overload function in viewDidLoad() in swift

问题描述

无法快速加载viewDidLoad()中的功能. 它给出错误definition conflict with previous value" at "func joinString(#strings: String...) -> String {

Unable to overload function in viewDidLoad() in swift. It gives error definition conflict with previous value" at "func joinString(#strings: String...) -> String {

override func viewDidLoad() {
    super.viewDidLoad()
    func joinString(#strings: String[]) -> String {
            var str = "" 
            for s in strings {
                str += s
            }
            return str
        }
    func joinString(#strings: String...) -> String {
            return joinString(strings: strings)
        }
    println(joinString(strings : ["I", "am", "an", "array"]))
    println(joinString(strings : "I", "am", "an", "array"))
}

推荐答案

对我来说，这似乎是一个Swift错误(或未记录的限制). 函数/方法重载通常可以正常工作，即使使用数组vs可变参数也是如此:

This looks like a Swift bug (or an undocumented restriction) to me. Function/method overloading works generally, even with array vs variadic parameters:

class MyClass {

    func foo(arg: Int) { println("An integer") }
    func foo(arg: Double) { println("A double") }

    func joinString(#strings: String[])  { println("An array") }
    func joinString(#strings: String...)  { println("Variadic parameters")}

    func test() {
        foo(2)
        foo(3.14)
        joinString(strings : ["I", "am", "an", "array"])
        joinString(strings : "I", "am", "an", "array")
    }
}

并产生预期的输出:

An integer
A double
An array
Variadic parameters

但是重载不适用于嵌套函数:

class MyClass {

    func test() {

        func foo(arg: Int) { println("An integer") }
        func foo(arg: Double) { println("A double") }
        // error: definition conflicts with previous value

        func joinString(#strings: String[])  { println("An array") }
        func joinString(#strings: String...)  { println("Variadic parameters")}
        // error: definition conflicts with previous value

        func test() {
            foo(2)
            foo(3.14)
            joinString(strings : ["I", "am", "an", "array"])
            joinString(strings : "I", "am", "an", "array")
        }
    }
}

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