C# Arrays



Let assume that we have to calculate the area of 5 rectangles. We can declare 5 variables each for length and width and then another 5 variables for the area as follows. 


    int length1,length2,length3,length4,length5;
    int breadth1,breadth2, breadth3,breadth4, breadth5; 	
    int area1,area2, area3, area4,area5 ;

While this is pefectly correct way to define the variables in this way, C# provides the concept of array.Here is how you do the same thing using arrays. 



    int[] length;
    int[] breadth; 	
    int[] area;


The statement int[] length says that length is an array of type int. C# is different from other languages in that [] comes after the type instead of the identifier.

Let us now go ahead an write a program that will print the areas of 5 rectangles. 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ArrayExample
{
        class Program
    {      
        static void Main(string[] args)
        {
            int[] length;
            int[] breadth;
            int[] area;

            length = new int[5];
            breadth = new int[5];
            area = new int[5];

            int i;

            length[0] = 10; length[1] = 20; length[2] = 30; length[3] = 40; length[4] = 50;
            breadth[0] = 5; breadth[1] = 15; breadth[2] = 25; breadth[3] = 35; breadth[4] = 45;

            for (i = 0; i <= 4; i++)
            {
                area[i] = length[i] * breadth[i];
                Console.Write("Area = ");
                Console.WriteLine(area[i]);
            }

            Console.ReadLine();

        }
    }
}

If we execute this example we get the following output 

	
Area = 50
Area = 300
Area = 750
Area = 1400
Area = 2250


Arrays help organize the codes. The statements 


            length = new int[5];
            breadth = new int[5];
            area = new int[5];

create instance of the array types. Now instead of length1, length2, length3, length4 and length5 we have length[0],length[1],length[2],length[3],length[4]. Note that the array index starts from 0 and not 1.

I have just covered the very basic concept of array. You should also explore the two dimensional arrays and some more topics. I will cover them when I get time. You may write at referencedesigner@yahoo.com or you may place your questions at Reference Designer Forum and I will attempt to answer it.