如何在iOS Swift中自定義Indexpath.row值

Question

我只想檢索表視圖中的某些索引項。 例如：我有：

let array1 = ["one","two","three","four","two","one","three"] 
let array2 = ["dog","cat","lion","tiger","elephant","eagle","peacock"]

var duplicatedDict : [String:[Int]] = [:]
for (index,dateString) in array1.enumerated() {
    if(duplicatedDict[dateString] == nil){
        duplicatedDict[dateString] = [index]
    }else{
        duplicatedDict[dateString]?.append(index)
    }
}

print(duplicatedDict)
//output :  ["three": [2, 6], "four": [3], "one": [0, 5], "two": [1, 4]]

當我得到值“ three”時，我必須只獲得array2 2nd和6th（2和6是字符串“ three”在array1中的索引值）索引。

輸出應該在我的UItableView行中（“獅子和孔雀”）。 如何自定義表格視圖以獲取上述輸出？

Answer 1

使用Swift4中的新default參數可以大大簡化duplicatedDict Dict的生成：

let array1 = ["one","two","three","four","two","one","three"]
let array2 = ["dog","cat","lion","tiger","elephant","eagle","peacock"]

var duplicatedDict = [String:[Int]]()
for (index, val) in array1.enumerated() {
    duplicatedDict[ val, default:[] ].append(index)
}

print(duplicatedDict)

一旦有了它，就可以輕松地從array2獲取相應的元素：

if let indexes = duplicatedDict["three"] {
    let animals = indexes.map { array2[$0] }
    print(animals)
}