ios - 如何将变量设置为从 0 开始并通过嵌套 for 循环 Swift 2 中的每个循环获得一个级别

Question

所以这是 swift 2 中嵌套 for 循环的一个例子。在它的正上方和正下方有一个 for 循环，一个接一个地工作。每次调用 for 循环时，我都想爬一个级别。通常，如果这是一个 for 循环，它会自动发生，但由于它是一个嵌套的 for 循环，我需要它运行一次，然后跳转到下一个 for 循环。

问题是 var u 为 0，它总是设置为 0，并且总是从那里开始。有没有办法让它变成 post place[u] = place[++] 的形式？

placeLoop: for aPlace in place {
                print("\(aPlace)")
                print(" ")
                var u : Int = 0
                if aPlace == place[u] {
                    place[u] = place[++u]
                    //This is the manual way to achieve what I want but I have 105 records I want to iterate through, there has to be a better way to do this.
                    //place[u] = var place[u]
                    //place[1] = place[2]
                    //place[2] = place[3]
                    //if aPlace is equal to place0 then 0 = 1, next loop 1 = 2, next loop 2 =3
                    //you can't ++ a "String which place[with an index] is.

我一直在阅读这个 documentation并查看了许多不同的 stackoverflow 问题，但到目前为止没有任何帮助......我正在考虑一个 switch 语句，但不确定它是否会有所不同。

编辑:

for a in coor {
    for aPlace in place {
         for aPass in pass {


}}}

数据为 geojson 格式: 颜色:双(2343.90) 地方:字符串(“asdfsa”) pass: String ("asdfkkrr")

还有3条记录

我需要它按以下顺序在我的代码中进一步输入: coor1、place1 和 pass1，然后是 coor2、place2 和 pass2，等等。

Answer 1

在第一个 for 循环之外定义 u 变量，在外部循环结束时定义 u += 1

检查这个

var u : Int = 0
placeLoop: for aPlace in place {
             print("\(aPlace)")
             print(" ")

             if aPlace == place[u] {
             place[u] = place[++u]
             //This is the manual way to achieve what I want but I have 105 records I want to iterate through, there has to be a better way to do this.
             //place[u] = var place[u]
             //place[1] = place[2]
             //place[2] = place[3]
             //if aPlace is equal to place0 then 0 = 1, next loop 1 = 2, next loop 2 =3
             //you can't ++ a "String which place[with an index] is.
             u += 1

希望对你有帮助，谢谢