如何将数组的每个元素乘以 Swift 中下一个数组的每个元素？

Question

我有两个数组。

let quntityArr = ["1","3","4","7"]

let priceArr = ["£129.95", "£179.95","£169.95","£199.85"]

我想通过以下方式将这两个数组相乘

let totalArr = ["1*£129.95", "3*£179.95", "4*£169.95", "7*£199.85"]

在这里，我想用这些产品数量计算每个价格。

Answer 1

你需要

let quntityArr:[Double] = [1,3,4,7]

let priceArr = [129.95, 179.95,169.95,199.85]

let totalArr = zip(quntityArr, priceArr).map { "£\($0 * $1)" }

print(totalArr)

Answer 2

假设您的输入数据以字符串数组的形式提供。

1。输入数据

let quntityArr = ["1","3","4","7"]
let priceArr = ["£129.95", "£179.95","£169.95","£199.85"]

2。转换 Int 和 Double 数组中的输入数据

let quantities = quntityArr
    .compactMap(Int.init)
let prices = priceArr
    .map { $0.dropFirst() }
    .compactMap (Double.init)

3。验证没有丢弃任何输入值

assert(quntityArr.count == quantities.count)
assert(priceArr.count == prices.count)

4。算算

let results = zip(quantities, prices).map { Double($0) * $1 }.map { "£\($0)"}

5。结果

["£129.95", "£539.8499999999999", "£679.8", "£1398.95"]