C#: Count a specified character (both cases) in a given string

Last update on June 24 2025 12:57:34 (UTC/GMT +8 hours)

Count Specific Character in String

Write a C# Sharp program to count a specified character (both cases) in a given string.

Sample Solution:

C# Sharp Code:

using System;

namespace exercises
{
    class Program
    {
        // Main method where the program execution begins
        static void Main(string[] args)
        {
            // Calls the test function with different string arguments and characters, and prints the results
            Console.WriteLine(test("PHP Exercises", 'E', 'e')); // Output: 2
            Console.WriteLine(test("Latest News, Breaking News LIVE", 'A', 'a')); // Output: 3
        }

        // Function to count occurrences of characters in a string (case-insensitive)
        public static int test(string str1, char uc, char lc)
        {
            // Using Split method to count occurrences of characters (case-insensitive)
            // Splitting the string using provided uppercase and lowercase characters as separators,
            // then getting the count of splits minus 1 (as the count of splits equals occurrences)
            return str1.Split(uc, lc).Length - 1;
        }
    }
}

Sample Output:

3
2

Flowchart:

Sample Solution-1:

C# Sharp Code:

using System;
using System.Linq;

namespace exercises
{
    class Program
    {
        // Main method where the program execution begins
        static void Main(string[] args)
        {
            // Calls the test function with different string arguments and characters, and prints the results
            Console.WriteLine(test("PHP Exercises", 'E', 'e')); // Output: 2
            Console.WriteLine(test("Latest News, Breaking News LIVE", 'A', 'a')); // Output: 3
        }

        // Function to count occurrences of specified characters in a string (case-insensitive)
        public static int test(string str1, char uc, char lc)
        {
            // Using LINQ's Where method to filter characters that match the specified uppercase or lowercase characters,
            // then using Count method to count the occurrences of matching characters
            return str1.Where(ch => (ch == lc || ch == uc)).Count();
        }
    }
}

Sample Output:

3
2

Flowchart:

For more Practice: Solve these Related Problems:

Write a C# program to count how many vowels appear in a given string.
Write a C# program to count occurrences of every character in a string (case-insensitive).
Write a C# program to count all alphanumeric characters excluding punctuation in a string.
Write a C# program to count how many times the most frequent character appears in a string.

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