arrays - 如何计算数组的正确索引

Question

我已经实现了一个 tableView，它的工作方式类似于下面的示例。我想为数组计算正确的索引，这样它就不会超出范围。我正在努力实现单元格 1 成为空间 2nd 成为具有数据的单元格并重复

 let array = ["0","1","2"] // this is the data with comes for the server so if the count is 3 the cell with data will be 3 and 3 will be just empty cell

 let totalCount = array.count*2

 for i in 0...totalCount {
     if i % 2 == 1{
         //Cell with data is shown here 
         print("Index: \(i-1)") // i'm doing somthing wrong here i need the i to be Index to be "0,1,2"
         print(array[i-1]) // how do i print the data from array at Index 0,1,2
     }else {
         //Space Cell
     }

 }

Answer 1

正如我在评论中提到的，总会有一个点，其中 i-1 将大于 array.count。我猜你想实现这个:

Cell: 0; empty cell
Cell: 0; Index 0
Value: 0
Cell: 2; empty cell
Cell: 2; Index 1
Value: 1
Cell: 4; empty cell
Cell: 4; Index 2
Value: 2
Cell: 6; empty cell

可以这样实现:

let array = ["0","1","2"]

let totalCount = array.count*2

for i in 0...totalCount {
    if i % 2 == 1{
        //Cell is shown here
        print("Cell: \(i-1); Index \(i/2)")
        print("Value: \(array[i/2])")
    }else {
        //Space Cell
        print("Cell: \(i); empty cell")
    }

}

i-1 应该是单元格的索引，而不是数组中数据的索引。单元格中显示的数据索引应改为 i/2，以确保此值永远不会大于 array.count。