查找一个字符串数组中有多少个元素

Question

I'm trying to find how many elements are in my string array, so I can add to that array from the first empty element.

Here's what I've tried to do:

int arrayLength = 0;
string[] fullName = new string[50];

if (fullName.Length > 0)
{
    arrayLength = fullName.Length - 1;
}

and then from that refer to the first available empty element as:

fullName[arrayLength] = "Test";

I can also use this to see if the array is full or not, but my problem is arrayLength is always equal to 49, so my code seems to be counting the size of the entire array, not the size of the elements that are not empty.

Cheers!

Answer 1

you can use this function to calculate the length of your array.

private int countArray(string[] arr)
{
    int res = arr.Length;

    foreach (string item in arr)
    {
        if (String.IsNullOrEmpty(item))
        {
            res -= 1;
        }
    }

    return res;
}

EDIT : To find the first empty element

private int firstEmpty(string[] arr)
{
    int res = 0;

    foreach (string item in arr)
    {
        if (String.IsNullOrEmpty(item))
        {
            return res;
        }
        res++;
    }

    return -1; // Array is full
}

Answer 2

I'm trying to find how many elements are in my string array,

array.Length

so I can add to that array from the first empty element.

Array's don't have empty elements; there's always something in there, though it could be null .

You could find that by scanning through until you hit a null, or by keeping track each time you add a new element.

If you're going to add new elements then, use List<string> this has an Add() method that will do what you want for you, as well as resizing when needed and so on.

You can likely then just use the list for the next part of the task, but if you really need an array it has a ToArray() method which will give you one.

Answer 3

因此，如果您想使用数组而不是列表，您仍然可以简单地获取空元素的数量，如下所示：

int numberOfEmptyElements = fullName.Count(x => String.IsNullOrEmpty(x));

Answer 4

Try the below code

    string[] fullName = new string[50];

    fullName[0] = "Rihana";
    fullName[1] = "Ronaldo";

    int result = fullName.Count(i => i != null);

in result you will have the number of occupied positions. In this case 2, cause 2 arrays are filled. From there you can count the empty. :)