How can I count the number of elements in an array?

Question

I have this array:

var categoryGroups = new[] {
    new CategoryGroupSource { Id = 1,  Name = "Conversation" },
    new CategoryGroupSource { Id = 2,  Name = "Business" },
    new CategoryGroupSource { Id = 3,  Name = "Education" }
};

I tried to do a count on this:

categoryGroups.Count

But it is giving me an error saying this will only work with a list. Can someone give me advice on this?

Note I am also doing this:

foreach (CategoryGroupSource categoryGroup in categoryGroups)
{
    db.Insert(categoryGroup);
}

Does the foreach work for arrays and lists?

Answer could have been found easily on google/MSDN – CSharped Dec 07 '16 at 04:54 — CSharped, Dec 07 '16 at 04:54

score 8 · Accepted Answer · answered Dec 07 '16 at 04:53

8

use categoryGroups.Length for the arrays

var categoryGroups = new[] {
            new CategoryGroupSource { Id = 1,  Name = "Conversation" },
            new CategoryGroupSource { Id = 2,  Name = "Business" },
            new CategoryGroupSource { Id = 3,  Name = "Education" }
        };

int count = categoryGroups.Length;

Does the foreach work for arrays and lists?

Yes.

Using foreach with Arrays (C# Programming Guide)

answered Dec 07 '16 at 04:53

Damith

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Pros and Cons using array for Generic? – Aizen Dec 07 '16 at 04:57
@Aizen Popular question http://stackoverflow.com/questions/434761/array-versus-listt-when-to-use-which – Damith Dec 07 '16 at 04:59

score 1 · Answer 2 · edited May 23 '17 at 12:30

1

You might have used

categoryGroups.Length

Every array has a Length. In the C# language we access the Length property on a non-null array. Length has no parentheses, as it is a property. It is read-only—you cannot assign Length.

And yes of-course foreach works for arrays and list. and if you wanted to see Why List is better than Arrays you can read more here

edited May 23 '17 at 12:30

Community

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answered Dec 07 '16 at 04:53

Mohit Shrivastava

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score 1 · Answer 3 · answered Dec 07 '16 at 04:54

1

foreach works of arrays and lists

For Counting no of element in array

change

categoryGroups.Count

to

categoryGroups.Length

answered Dec 07 '16 at 04:54

Hassan Tariq

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score 0 · Answer 4 · answered Dec 07 '16 at 05:02

In .NET, arrays and strings (which are technically special character arrays) have a Length property, and just about every other collection has a Count property for this counting elements.

In addition to this, the System.Linq namespace provides a Count() extension method for the IEnumerable<T> interface, which most collections implement. So for an array you can also use myArray.Count(), if you're using System.Linq;.

Note that Count() is a method on arrays and any collection implementing IEnumerable<T>, while Count is a property of some collections.

score 0 · Answer 5 · answered Dec 07 '16 at 05:03

0

foreach works with all types that implements IEnumerable.

You were not able to access .count property because it is available for List types, but you are using Array.

answered Dec 07 '16 at 05:03

Sateesh Pagolu

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score 0 · Answer 6 · answered Dec 07 '16 at 05:05

0

I agree if you just want it to say the amount of values in the array you could just print the length value of the array.

answered Dec 07 '16 at 05:05

matttootrill

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How can I count the number of elements in an array?

6 Answers6