C#: Compare two string whether they are equal or not

Last update on December 20 2024 12:44:25 (UTC/GMT +8 hours)

Write a program in C# Sharp to compare two strings without using a string library functions.

Sample Solution:-

C# Sharp Code:

using System;

// Define the Exercise6 class
public class Exercise6
{  
    // Main method - entry point of the program
    public static void Main() 
    {
        string str1, str2; // Declare two string variables
        int flg = 0; // Initialize a flag variable to determine the comparison result
        int i = 0, l1, l2, yn = 0; // Declare variables for iteration and string lengths
	
        // Prompt the user to compare two strings
        Console.Write("\n\nCompare two strings whether they are equal or not:\n");
        Console.Write("------------------------------------------------------\n"); 	
        Console.Write("Input the 1st string: ");
        str1 = Console.ReadLine(); // Read the first input string
	
        Console.Write("Input the 2nd string: ");
        str2 = Console.ReadLine(); // Read the second input string

        l1 = str1.Length; // Get the length of the first string
        l2 = str2.Length; // Get the length of the second string

        // Compare checking when the strings are equal in length
        if (l1 == l2)
        {
            for (i = 0; i < l1; i++)
            {
                if (str1[i] != str2[i])
                {
                    yn = 1;
                    i = l1; // Exit the loop if a difference in characters is found
                }
            }
        }

        // Initialize the flag where they are equal, smaller, or greater in length
        if (l1 == l2)
            flg = 0;
        else if (l1 > l2)
            flg = 1;
        else if (l1 < l2)
            flg = -1;

        // Display messages based on the comparison result
        if (flg == 0)
        {
            if (yn == 0)
                Console.Write("\nThe length of both strings are equal and both strings are same.\n\n");
            else
                Console.Write("\nThe length of both strings are equal but they are not same.\n\n");
        }
        else if (flg == -1)
        {
            Console.Write("\nThe length of the first string is smaller than the second.\n\n");
        }
        else
        {
            Console.Write("\nThe length of the first string is greater than the second.\n\n");
        }
    }
}

Sample Output:

Compare two strings whether they are equal or not :                     
------------------------------------------------------                 
Input the 1st string : This is the first string.                       
Input the 2nd string : This is the second string.                      
                                                                       
The length of the first string is smaller than second.

Flowchart:

C# Sharp Code Editor:

Click to Open Editor

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