Swift:在“:"之前有两个变量的原因 [英] Swift: reason for two variables before ":"

问题描述

这是Apple的官方Doc示例:

Here's Apple's official Doc example:

class Counter {
    var count: Int = 0
    func incrementBy(amount:Int, numberOfTimes times:Int){
        count += amount * times
    }
}

var counter = Counter()
counter.incrementBy(2, numberOfTimes: 8)

实际上，以下代码有什么区别:

Actually, what's the difference with the following codes:

class Counter {
    var count: Int = 0
    func incrementBy(amount:Int, numberOfTimes:Int){
        count += amount * numberOfTimes
    }
}

var counter = Counter()
counter.incrementBy(2, numberOfTimes: 8)

为什么将times放在正式文档中? 我是编程新手，有人可以解释其背后的理论吗? 谢谢！

why times is put inside in the official Doc? i'm new to programming, can someone explain the theory behind? Thx!!

推荐答案

numberOfTimes是外部参数名称/标签，而times是内部参数名称，仅在函数内部使用.参见

numberOfTimes is the external parameter name/label, whereas times is the internal parameter name, used only inside the function. See Function Parameter Names for more information.

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