Count occurrences of a character within a string in C#

This post will discuss how to count occurrences of a given character in a string in C#.

1. Using `Enumerable.Count()` method (`System.Linq`)

The recommended solution is to use LINQ’s Count() method to count occurrences of the given character in a string. This method is demonstrated below:

using System;

using System.Linq;

public class Example

{

public static void Main()

{

string str = "Techie Delight";

char ch = 'e';

int freq = str.Count(f => (f == ch));

Console.WriteLine(freq);

}

Output: 3

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2. Using `Enumerable.Where()` method (`System.Linq`)

Here’s another LINQ solution that uses the Where() method to filter the string. The following code example shows how to use this:

using System;

using System.Linq;

public class Example

{

public static void Main()

{

string str = "Techie Delight";

char ch = 'e';

int freq = str.Where(x => (x == ch)).Count();

Console.WriteLine(freq);

}

Output: 3

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3. Using `String.Split()` method

Here, the idea is to split the string with a specified character using the String.Split() method and use the Length property of the resultant string array to determine the count. This is demonstrated below:

using System;

public class Example

{

public static void Main()

{

string str = "Techie Delight";

char ch = 'e';

int freq = str.Split(ch).Length - 1;

Console.WriteLine(freq);

}

Output: 3

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4. Using `foreach` loop

We can also write our own logic for this simple task. The idea is to iterate over the characters in the string using a foreach loop and keep a matching character count.

using System;

public class Example

{

public static void Main()

{

string str = "Techie Delight";

char ch = 'e';

int freq = 0;

foreach (char c in str)

{

if (c == ch) {

freq++;

}

Console.WriteLine(freq);

}

Output: 3

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5. Using `Regex.Matches()` method

Regex.Matches() method is used to search for the specified input string for all occurrences of the specified regular expression. We can use it as follows to count occurrences of a character within a string.

using System;

using System.Text.RegularExpressions;

public class Example

{

public static void Main()

{

string str = "Techie Delight";

char ch = 'e';

int freq = Regex.Matches(str, ch.ToString()).Count;

Console.WriteLine(freq);

}

Output: 3

Download Run Code

That’s all about counting occurrences of a character within a string in C#.

Count occurrences of a character within a string in C#

1. Using Enumerable.Count() method (System.Linq)

2. Using Enumerable.Where() method (System.Linq)

3. Using String.Split() method

4. Using foreach loop

5. Using Regex.Matches() method

1. Using `Enumerable.Count()` method (`System.Linq`)

2. Using `Enumerable.Where()` method (`System.Linq`)

3. Using `String.Split()` method

4. Using `foreach` loop

5. Using `Regex.Matches()` method