C#: Compare two substrings that only differ in case

Last update on August 25 2025 12:51:27 (UTC/GMT +8 hours)

Write a C# Sharp program to compare two substrings that only differ in case. The first comparison ignores case and the second comparison considers case.

Sample Solution:-

C# Sharp Code:

using System;

// Define the Example22 class
class Example22
{
    // Main method - entry point of the program
    public static void Main()
    {
        // Define and initialize string variables
        String str1 = "COMPUTER"; // String 1
        String str2 = "computer"; // String 2
        String str;               // String to store comparison result
        int result;               // Result of the comparison

        // Display initial strings
        Console.WriteLine();
        Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);

        // Ignore case while comparing substrings
        Console.WriteLine("Ignore case:");
        // Compare a substring of str1 starting at index 2 with a substring of str2 starting at index 2, each with a length of 2, ignoring case
        result = String.Compare(str1, 2, str2, 2, 2, true);
        // Determine the relationship between the compared substrings
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        // Display the comparison result
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);

        Console.WriteLine();
        // Honor case while comparing substrings
        Console.WriteLine("Honor case:");
        // Compare a substring of str1 starting at index 2 with a substring of str2 starting at index 2, each with a length of 2, honoring case
        result = String.Compare(str1, 2, str2, 2, 2, false);
        // Determine the relationship between the compared substrings
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        // Display the comparison result
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);
    }
}

Sample Output:

str1 = 'COMPUTER', str2 = 'computer'                                                                          
Ignore case:                                                                                                  
Substring 'MP' in 'COMPUTER' is equal to substring 'mp' in 'computer'.                                        
                                                                                                              
Honor case:                                                                                                   
Substring 'MP' in 'COMPUTER' is greater than substring 'mp' in 'computer'.

Flowchart :

Go to:

PREV : Write a C# Sharp program to compare (less than, greater than, equal to ) two substrings.
NEXT : Write a C# Sharp program to compare two substrings using different cultures and ignoring the case of the substrings.

C# Sharp Code Editor:

Contribute your code and comments through Disqus.