C# Language Count and LongCount


Example

Count returns the number of elements in an IEnumerable<T>. Count also exposes an optional predicate parameter that allows you to filter the elements you want to count.

int[] array = { 1, 2, 3, 4, 2, 5, 3, 1, 2 };

int n = array.Count(); // returns the number of elements in the array
int x = array.Count(i => i > 2); // returns the number of elements in the array greater than 2

LongCount works the same way as Count but has a return type of long and is used for counting IEnumerable<T> sequences that are longer than int.MaxValue

int[] array = GetLargeArray();

long n = array.LongCount(); // returns the number of elements in the array
long x = array.LongCount(i => i > 100); // returns the number of elements in the array greater than 100