.net array - difference between “Length”, “Count()” and “Rank”

Question

What\'s the difference between \"Length\", \"Count()\" and \"Rank\" for .net array?

Answer 1

Length is a property of Array since C# 1.x

Count()is an extension method of IEnumerable, because now every T[] implements IEnumerable implicitly.

Note that for an array, Count() is usually much slower than Length, because accessing Length property is O(1), while Count is for IEnumerable, so the program needs to go through the collection and get its count, that is O(n).

Rank gives the demensions of the array.