Question

swift中的zip函数

   let words = ["one", "two", "three", "four"]
   let numbers = 1...4

   for (word, number) in zip(words, numbers) {
      print("\(word): \(number)")
   }

  // Prints "one: 1"
  // Prints "two: 2
  // Prints "three: 3"
  // Prints "four: 4"

但如果我想将[(one,1),(two,2),(three,3),(four,4)]转置为["one", "two", "three", "four"]和[1,2,3,4]。

如何在swift中执行此操作，在Python中是否有类似的直接转换方法？

Answer 1

您可以运行map两次以“解压缩”数组：

let arr = [("one", 1), ("two", 2), ("three", 3), ("four", 4)]

let arr1 = arr.map { $0.0 }
let arr2 = arr.map { $0.1 }

print(arr1) // ["one", "two", "three", "four"]
print(arr2) // [1, 2, 3, 4]

您也可以一次性使用reduce执行此操作：

let (arr3, arr4) = arr.reduce(([], [])) { ($0.0 + [$1.0], $0.1 + [$1.1]) }

print(arr3) // ["one", "two", "three", "four"]
print(arr4) // [1, 2, 3, 4]

如何在swift中使用zip函数转置

1 个答案: