Indexing

Every element of an array has an index which is simply its position in the array. The first element has the index 0, the second element has the index 1, and so on. Since indices start from 0, the last element's index is 1 less than the size of the array (size - 1).

The following illustration is a slightly modified version of the one from the last chapter however this time the elements have their corresponding indices written beneath them:

We can access an element of an array using the following syntax:

main


              1
            
arrayName[index];

For-example:

main


              12345678910111213
            
using System;

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
			int[] studentMarks = new int[50];
			Console.WriteLine(studentMarks[9]); // Output: 0
        }
    }
}

In the above code, we access the 10th element of the array and it outputs 0. This is because when we create a new empty array it is automatically filled with relevant zero values according to its data type.

Each element of an array is essentially a variable. We can access and modify an element of an array using the following syntax:

main


              1
            
arrayName[index] = newValue;

For-example:

main


              1234567891011121314151617181920
            
using System;

namespace ConsoleApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
			int[] studentMarks = new int[50];

			studentMarks[0] = 50;
			studentMarks[1] = 77;
			studentMarks[2] = 97;

			Console.WriteLine(studentMarks[0]);
			Console.WriteLine(studentMarks[1]);
			Console.WriteLine(studentMarks[2]);
        }
    }
}

Everything was clear?

Section 5. Chapter 3