How to Write a C# program to find the reverse number of a number and  C# program to reverse a string.

What is reverse a number ?

Reverse a numbers, or more specifically pairs of reversible numbers, are whole numbers in which the digits of one number are reverse of the digits in another number. for example-  2847 is reverse of a number 7482. We can reverse a number in C# using loop and arithmetic operators.

Example: Here what we actually want from our program to give output of a given input as shown below.

Input: 123455

Output: 554321

Algorithm for Reversing any Number

1. Input: num
2.  Initialize rev_num =  0
3. Loop while num > 0
   •Multiply rev_num by 10 and add remainder of num
   •divide by 10 to rev_num
   •rev_num = rev_num*10 + num%10;
   •Divide num by 10
4. Return or print rev_num

C# Program to Reverse a Number

using System;
 
namespace CSharpProgram
{
    class Program
    {
        static void Main(string[] args)
        {
            int n, rev = 0, rem;
            Console.Write("Enter a number to find the reverse: ");
            n = int.Parse(Console.ReadLine());
            while (n != 0)
            {
                rem = n % 10;
                rev = rev * 10 + rem;
                n /= 10;
            }
            Console.Write("The Reversed Number of: "+n+" is " + rev);
            Console.ReadLine();
        }
        
    }
}

Output:

What is Reversing a String ?

The way we can reverse a number same we can reverse a string. In reversing of a string the alphabets of a word will swap their places like first letter will take place of the last letter.

Example- The result we will get from this program like as shown below.

Input: Hello!

Output: !olleH

C# Program to Reverse a String using For Loop

using System;
namespace LogicalPrograms
{
    public class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a String : ");
            string name = Console.ReadLine();
            string reverse = string.Empty;
            for (int i = name.Length - 1; i >= 0; i--)
            {
                reverse += name[i];
            }
            Console.WriteLine($"The Reverse string is : {reverse}");
            Console.ReadKey();
        }
    }
}

Output:

C# Program  to Reverse a String using Foreach Loop

using System;
namespace LogicalPrograms
{
    public class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a String : ");
            string name = Console.ReadLine();
            string reverse = string.Empty;
            foreach (char c in name)
            {
                reverse = c + reverse;
            }
            
            Console.WriteLine($"The Reverse string is : {reverse}");
            Console.ReadKey();
        }
    }
}

Output:

So in this way we can make program in C#  to Reverse any number or a string.