Create non zero indexed arrays in C#

99.99% of the time, we write our code with zero indexed arrays. However, C# allows us to create non zero based (single or multi dimensional arrays).

The syntax from MSDN is:

public static Array CreateInstance(
                Type elementType,
                int[] lengths,
                int[] lowerBounds)

CreateInstance is a static method available in Array class. Here, variable "lengths" indicates the dimension of the array and "lowerBounds" indicates what is the starting lower bound of each dimension array.

To understand the concept in a simple way, let’s consider the single dimension array and the following code is used to create the instance

// Create the instance of an Array
Array myArray = Array.CreateInstance(typeof(int), new[] { 4 }, new[] { 2011 });

// Set the values to array
myArray.SetValue(5, 2005);
myArray.SetValue(6, 2006);
myArray.SetValue(7, 2007);
myArray.SetValue(8, 2008);   

// Display the lower bound of the array
Console.WriteLine(myArray.GetLowerBound(0));  

// Display the upper bound of the array
Console.WriteLine(myArray.GetUpperBound(0));  

// Display all the items in the array
for (int i = myArray.GetLowerBound(0); i <= myArray.GetUpperBound(0); i++)
    Console.WriteLine(myArray.GetValue(i));

Pros:

1. More meaningful index, based on scenario.

Cons:

1. Slow performance.
2. Non CLS complaint.

Advertisement