无法使用int的参数列表调用avgArray

I'm new to Swift, and just start to learn this language by following The Swift Programming Language. In this book, there is an exercise question that ask me to write a function to calculate the average of an array. Here is my code:

我是Swift的新手，只是按照Swift编程语言开始学习这门语言。在本书中，有一个练习题，要求我编写一个函数来计算数组的平均值。这是我的代码：

func avgArray(elements: Int...)->Double{
var avg:Double = 0
var sum = 0
var count = 0
for element in elements {
    sum += element
    count += 1
}
avg = Double(sum) / Double(count)
return avg
}

let numberlist = [2,3,6,7,2,7,0,9,12]
let average = avgArray(numberlist)

I don't know why I can't pass the array into my function. Also, is there a way besides using a count variable to keep track of the number of elements in the array?

我不知道为什么我不能将数组传递给我的函数。另外，除了使用count变量来跟踪数组中的元素数量之外，还有其他方法吗？

1 个解决方案

#1

I don't know why I can't pass the array into my function.

我不知道为什么我不能将数组传递给我的函数。

Your elements is not an array, it is a variadic parameter. Change it to

您的元素不是数组，它是一个可变参数。将其更改为

func avgArray(elements: [Int])->Double{

and you should be good to go.

你应该好好去。

is there a way besides using a count variable to keep track of the number of elements in the array?

有没有办法除了使用count变量来跟踪数组中的元素数量？

Absolutely. count property of the array itself. You can use it in your code like this:

绝对。 count数组本身的属性。您可以在代码中使用它，如下所示：

avg = Double(sum) / Double(elements.count)

#1