arrays - 如何迭代数组并将每个元素与 Swift 中的其他元素进行比较

Question

我有一个数组。我尝试分析每个元素(每个元素都是一个字符)并比较每个元素是否单独等于另一个字符，如下所示:

(以下代码不正确，仅作说明)

let array = ["5","a","5","8","l","j"]
var finalString = ""
for i in array {
    if array[i] = ["^0-9"] {
        //Compares if the element in position i is equal to a number between 0 - 9
        finalString + "1 " //or do something else
    } else if array[i] = ["^a-z"] {
        //Compares if the element in position i is equal to a character between a - z
        finalString + "2 " //or do something else
    }
}
print(finalString)
//Expected output
// 1 2 1 1 2 2

我希望我的问题的解释很清楚。

Answer 1

我想了解有关可能的输入值的更多信息。

let array = ["5","a","5","8","l","j"]

let finalString = array.reduce("") { result, character in
    switch character {
    case "0"..."9": return result.appending("1 ")
    case "a"..."z": return result.appending("2 ")
    default: assertionFailure("\(character) is unexpected input"); return result
    }
}

print(finalString)