How can I count the number of elements in IEnumerator?

Question

I am getting all files in a directory by following code.

IEnumerator FILES = Directory.GetFiles(
                DIRECTORY_PATH).GetEnumerator();

How can I get the total number of files? There's no FILES.Count();

`Directory.GetFiles(..)` returns a `string[]` - i.e. an array. This has a `.Length` property on it. — canton7, Apr 17 '19 at 11:28
Possible duplicate of [Count the items from a IEnumerable without iterating?](https://stackoverflow.com/questions/168901/count-the-items-from-a-ienumerablet-without-iterating) — SucksAtJavascript, Apr 17 '19 at 11:29
Is there any reason that you need Enumerator from GetFiles(string) method? As already been suggested, GetFiles(string).Length will do just fine. — Yawar Murtaza, Apr 17 '19 at 11:32
In general, if all you have really is an `IEnumerator` instance, the way to get the count is to enumerate while counting :) — 500 - Internal Server Error, Apr 17 '19 at 11:33

Liquid Core · Accepted Answer · 2019-04-17T11:34:40.757

1

Directory.GetFiles(@"C:\yourdir").Length

will give you count directly

edited Apr 17 '19 at 11:34

answered Apr 17 '19 at 11:30

Liquid Core

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Fixed. To much used to Linq that I forgot about return type – Liquid Core Apr 17 '19 at 11:33
1

@GiladGreen it's true that there's no 'need' for 'System.Linq' here. Anyway, since an array is an `ICollection`, a LInQ `Count()` [is optimized to](https://referencesource.microsoft.com/System.Core/R/41ef9e39e54d0d0b.html) directly access the `Count` property of the `ICollection`; which in turn [returns the `Length` property of the array](https://referencesource.microsoft.com/mscorlib/system/array.cs.html#680). – Aly Elhaddad Apr 17 '19 at 11:40

score 1 · Answer 2 · answered Apr 17 '19 at 11:34

1

First you can get your files string[], count the numbers in it, then get your enumerator:

string[] files = Directory.GetFiles(DIRECTORY_PATH);
int count = files.Length;
IEnumerator enumerator = files.GetEnumerator();

answered Apr 17 '19 at 11:34

SᴇM

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score 0 · Answer 3 · answered Apr 17 '19 at 11:36

If you really want to stick with "GetEnumerator()" ...

IEnumerator files = Directory.GetFiles(DIRECTORY_PATH).GetEnumerator();
int count = 0;
while (files.MoveNext())
{
    count++;
}

// after this loop you will have total files count in count varibale.

How can I count the number of elements in IEnumerator?

3 Answers3