C# Split String
last modified April 20, 2025
This tutorial explores how to split strings in C# using the String.Split and Regex.Split methods, with practical examples for various scenarios.
Overview of String Splitting
The String.Split method divides a string into an array of substrings based on specified delimiters, such as characters or strings. For more complex patterns, Regex.Split uses regular expressions to define splitting criteria.
Split(Char[], Int32, StringSplitOptions) Split(Char, Int32, StringSplitOptions) Split(String[], Int32, StringSplitOptions) Split(String[], StringSplitOptions) Split(String, Int32, StringSplitOptions) Split(Char[], StringSplitOptions) Split(Char[], Int32) Split(Char, StringSplitOptions) Split(String, StringSplitOptions) Split(Char[])
String.Split offers ten overloads to handle different delimiter
types, counts, and options like removing empty entries.
Split(String, String, RegexOptions, TimeSpan) Split(String, String, RegexOptions) Split(String, Int32, Int32) Split(String, Int32) Split(String) Split(String, String)
Regex.Split provides seven overloads, enabling splits based on
regular expression patterns, with options for case sensitivity and timeouts.
Splitting a String by a Single Character
This example demonstrates the basic use of String.Split to divide a sentence into words using a space delimiter.
string text = "There is an old hawk in the sky";
string[] words = text.Split(' ');
Array.ForEach(words, Console.WriteLine);
The program splits a sentence into words by a space character, creating an array of substrings. The Array.ForEach method prints each word on a new line.
This simple approach is ideal for parsing text with consistent delimiters, such as space-separated words in a sentence. The output lists each word individually, demonstrating the split operation.
$ dotnet run There is an old hawk in the sky
Omitting Empty Entries
This example uses StringSplitOptions.RemoveEmptyEntries to exclude
empty substrings when splitting a string with multiple spaces.
string text = "There is an old hawk in the sky";
string[] words = text.Split(' ', StringSplitOptions.RemoveEmptyEntries);
Array.ForEach(words, Console.WriteLine);
The text contains multiple consecutive spaces, which could produce empty entries in the resulting array. By using StringSplitOptions.RemoveEmptyEntries, the program ensures only non-empty substrings are included.
This technique is useful for cleaning up text data with inconsistent spacing, such as user input or log files. The output shows only the actual words, with empty entries omitted.
$ dotnet run There is an old hawk in the sky
Splitting by Multiple Characters
This example splits a string using multiple delimiter characters, showcasing String.Split's ability to handle diverse separators.
string text = "falcon;eagle,forest,sky;cloud,water,rock;wind"; string[] words = text.Split([',', ';']); Array.ForEach(words, Console.WriteLine);
The program splits a string containing words separated by commas and semicolons.
The Split method accepts an array of characters as delimiters,
splitting the string whenever either character is encountered.
This approach is valuable for parsing data with multiple separators, such as CSV files with mixed delimiters. The output lists each word, demonstrating the successful split by both delimiters.
$ dotnet run falcon eagle forest sky cloud water rock wind
Limiting the Number of Substrings
This example limits the number of substrings produced by String.Split using the count parameter in an overloaded method.
string text = "falcon,eagle,forest,sky,cloud,water,rock,wind";
string[] words = text.Split(',', 4);
Array.ForEach(words, Console.WriteLine);
The program splits a comma-separated string into at most four substrings. The Split method stops splitting after reaching the specified count, leaving the remaining text as a single substring.
This technique is useful for extracting a fixed number of fields from structured data, such as the first few columns of a CSV row. The output shows the first three words as separate substrings, with the rest combined into the fourth.
$ dotnet run falcon eagle forest sky,cloud,water,rock,wind
Splitting by a String Delimiter
This example uses String.Split to divide a string based on a string delimiter, rather than a single character.
string text = "hawkxxowlxxvulturexxeagle";
string[] birds = text.Split("xx");
Array.ForEach(birds, Console.WriteLine);
The program splits a string using "xx" as the delimiter, producing an array of bird names. The Split overload accepting a string delimiter enables this functionality.
This method is ideal for parsing text with multi-character separators, such as log entries or custom-formatted data. The output lists each bird name, confirming the successful split.
$ dotnet run hawk owl vulture eagle
Splitting with Regex.Split
This example uses Regex.Split to split a string based on a regular expression pattern, handling complex delimiter scenarios.
using System.Text.RegularExpressions; string text = "There are\t\t many clouds in the \n sky."; Regex rx = new Regex(@"\s+", RegexOptions.Compiled); string[] data = rx.Split(text); Array.ForEach(data, Console.WriteLine);
The program splits a string containing tabs, multiple spaces, and a newline using a regular expression (\s+) that matches one or more whitespace characters. The RegexOptions.Compiled flag improves performance for repeated use.
Regex.Split is powerful for handling irregular delimiters, such as varying whitespace in text files. The output lists the non-empty substrings, showing effective splitting by the pattern. For more details, see the C# Regular Expressions tutorial.
$ dotnet run There are many clouds in the sky.
Joining Split Strings
This example demonstrates String.Join, which complements splitting by concatenating an array of strings with a specified separator.
List<string> words = ["falcon", "wood", "sky", "water"];
string text = string.Join(",", words);
Console.WriteLine(text);
The program joins a list of words into a single string, using a comma as the separator. String.Join is the inverse of String.Split, combining elements into a unified string.
This method is useful for formatting data, such as creating CSV strings or displaying lists. The output shows the words joined by commas, illustrating the reverse of the splitting process.
$ dotnet run falcon,wood,sky,water
Source
How to separate strings using String.Split in C#
In this article, we explored splitting strings in C# using String.Split and Regex.Split.
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