I have List<int>, where are write Numbers, from 0-1, now I need

1. find the first item which will contain the number “1”,
2. I NEED to save this item in the variable,
3. then I need compare this Variable to another item in list….

So my problem is: how can I save this variable, then compare it to another item in the list, BUT without replacing this variable by a List?

public static void Main()
{
   List<int> list = new List<int>();

    list.Add(0);
    list.Add(0);
    list.Add(1);
    list.Add(1);
    list.Add(0);
    list.Add(0);
    list.Add(1);

    for (int i = 0; i < list.Count-1; i  )
    {
        int temp;

        int count = 0; 


        if (list[i]>=1)
        {
         
            temp =list[i];
            if (temp == list[i   1])
            {
                count  ;
            }

        }
      
       
    }


}

CodePudding user response：

Define a variable with initial value (ex. -1). As long as the value is -1 this means the index not found yet. So, try the following:

// The index of first value of 1 in the list. -1 means not found yet
int indexFound = -1;

List<int> list = new List<int>();

list.Add(0);
list.Add(0);
list.Add(1);
list.Add(1);
list.Add(0);
list.Add(0);
list.Add(1);

for (int i = 0; i < list.Count-1; i  )
{
    // condition will not execute if first item with value 1 already found
    if (list[i] == 1 && indexFound == -1)
    {
        indexFound = i; // index of first value in list = 1
    }
   
   // compare the found value with any element in the list during the looping. Rephrase the condition as needed according to comparison required
   if (list[i] == indexFound)
   {
       Console.WriteLine("comparison of this Variable to another item in list");
        // do whatever needed
   }
}
Console.WriteLine(indexFound);