Count the number of strings in another string in C# / .NET

Counting occurrences of a string in another is done the same way in JavaScript: in C# / .NET, you'll use different approaches when searching for 1 character or multiple ones (different data type).
To count the number of times a character is found in a string, use the Split() method, which separates a text into array elements, using the character you passed as argument: // Letter "L" appears 5 times, once in uppercase: string str = "Learning C# can be helpful all the time."; int countL = str.Split('l').Length-1; MessageBox.Show( "Found that many times: " + countL.ToString() );
Note: don't forget subtract 1 from the array length, since splitting will always give you one more element than the number of times the character separator was found in the string.
The code above didn't return the expected result, because the Split() method is case-sensitive; as workaround, convert the string to upper- or lowercase before splitting - revised example: // Find all "L", regardless of letter casing: string str = "Learning C# can be helpful all the time."; int countL = str.ToLower().Split('l').Length-1; MessageBox.Show( "Letter l count is: " + countL.ToString() );
To count the number of times a string appears in another, pass the text to find as a regular expression pattern, counting with Regex.Matches - the code below is case-insensitive: string str = "The foxy fox jumps before dancing the Foxtrot."; // Make search case-insensitive with optional third argument: int fCount = Regex.Matches(str, "fox", RegexOptions.IgnoreCase).Count; MessageBox.Show("Occurrences of 'fox' in str = " + fCount.ToString());
Tip: include appropriate namespace at the top, with "using System.Text.RegularExpressions;".
Update: you can split strings with another string using an indirect construct (array overload).

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