C# 7 and .NET Core 2.0 High Performance

Arrays

An array is a collection that holds similar types of elements. Arrays of both value types and reference types can be created.

Here are few circumstances where arrays are useful:

• If the data is of a fixed, set length, using an array is a better option as it is faster than other collections, such as arraylists and generic lists
• Arrays are good to represent data in a multidimensional way
• They take less memory compared to other collections
• With arrays, we can iterate through elements sequentially

The following table shows the Big O notation for each operation that can be performed in an array:

Operations	Big O notation
Access by Index	O(1)
Search	O(n)
Insert at the end	O(n)
Remove at the end	O(n)
Insert ...