计算数组数组中的项目? [英] Count Items in an Array of Arrays?

问题描述

如果我有一个声明为

let compoundArray = [Array<String>]

是否有一个属性可以给我compoundArray中包含的所有数组中的字符串数?

is there a property that would give me the number of strings in all the arrays contained in compoundArray?

我可以通过将每个数组中的所有项相加来做到这一点:

I can do it by adding up all the items in each array within:

var totalCount = 0
for array in compoundArray {
   totalCount += array.count }
//totalCount = total items in all arrays within compoundArray

但是这似乎很笨拙，而且看来swift将具有Array的属性/方法来执行此操作，不是吗?

But that seems clunky and it seems that swift would have a property/method of Array to do this, no?

谢谢！

推荐答案

您可以为此使用joined或flatMap.

使用joined

Using joined

let count = compoundArray.joined().count

使用flatMap

Using flatMap

let count = compoundArray.flatMap({$0}).count

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