Swift 5：如何更新数组数组中的值？

Question

我正在尝试更新数组数组中的值，但我猜 for item in buffer 一定是在缓冲区中制作项目的副本，而不是提供对原始项目的引用。除了某种 for i=...{buffer[i][3]='Moved'} 之外，还有其他方法可以做到这一点吗？

        var buffer = [[String]]()
        let bufRemoved = buffer.filter({[=11=][3] == "Removal"})
        let bufAdded   = buffer.filter({[=11=][3] == "Addition"})

        let moved      = bufRemoved.filter({item in bufAdded.contains(where: {[=11=][2] == item[2]})})

        for var item in buffer {
            if moved.contains(where: {[=11=][2] == item[2]}) {
                switch item[3] {
                case "Removal":
                    item[3] = "Moved(out)"
                case "Addition":
                    item[3] = "Moved(in)"
                default:
                    break
                }
            }
        }

        let bufMoved   = buffer.filter({[=11=][3].contains("Move")})

Answer 1

一个解决方案是enumerate数组也有索引

    for (index, item) in buffer.enumerated() {
        if moved.contains(where: {[=10=][2] == item[2]}) {
            switch item[3] {
            case "Removal":
                buffer[index][3] = "Moved(out)"
            case "Addition":
                buffer[index][3] = "Moved(in)"
            default:
                break
            }
        }
    }

Swift 5：如何更新数组数组中的值？

Swift 5: How do I update values in an Array of arrays?

arrays

swift

swift5.1