c#restart for循環

Question

所以我有這幾行代碼：

string[] newData = File.ReadAllLines(fileName)
int length = newData.Length;
for (int i = 0; i < length; i++)
{
    if (Condition)
    {
       //do something with the first line
    }
    else
    {
      //restart the for loop BUT skip first line and start reading from the second
    }
}

我已經嘗試過使用 goto，但正如您所看到的，如果我再次啟動 for 循環，它將從第一行開始。

那么如何重新啟動循環並更改起始行（從數組中獲取不同的鍵）？

Answer 1

我認為這里的for loop是錯誤的循環類型，它沒有正確表達循環的意圖，並且肯定會向我建議您不要弄亂計數器。

int i = 0;
while(i < newData.Length) 
{
    if (//Condition)
    {
       //do something with the first line
       i++;
    }
    else
    {
        i = 1;
    }
}

Answer 2

只需更改 for 循環的index ：

for (int i = 0; i < newData.Length; i++) // < instead of <= as @Rawling commented.
{
    if (//Condition)
    {
       //do something with the first line
    }
    else
    {
      // Change the loop index to zero, so plus the increment in the next 
      // iteration, the index will be 1 => the second element.
      i = 0;
    }
}

請注意，這看起來像一個出色的意大利面條式代碼……更改 for 循環的索引通常表明您做錯了什么。

Answer 3

只需在else語句中設置i = 0 ； 然后循環聲明中的i++應將其設置為1 ，從而跳過第一行。

Answer 4

string[] newData = File.ReadAllLines(fileName)

for (int i = 0; i <= newData.Length; i++)
{
    if (//Condition)
    {
       //do something with the first line
    }
    else
    {
      //restart the for loop BUT skip first line and start reading from the second
      i = 0;
    }
}

Answer 5

您只需重置i並調整數組大小

int length = newData.Length; // never computer on each iteration
for (int i = 0; i < length; i++)
{
    if (condition)
    {
       //do something with the first line
    }
    else
    {
      // Resize array
      string[] newarr = new string[length - 1 - i];
      /*
       * public static void Copy(
       *    Array sourceArray,
       *    int sourceIndex,
       *    Array destinationArray,
       *    int destinationIndex,
       *    int length
       * )
       */
      System.Array.Copy(newData, i, newarr, 0, newarr.Length); // if this doesn't work, try `i+1` or `i-1`
      // Set array
      newData = newarr;
      // Restart loop
      i = 0;
    }
}