C# String Trim

Summary: in this tutorial, you will learn how to use the C# String Trim() method to remove the leading and trailing white spaces from a string.

Introduction to the C# String Trim() method

The String Trim() method allows you to remove the leading and trailing white spaces from a string. It returns a new string with the leading and trailing white spaces removed.

Here’s the syntax of the Trim() method:

public string Trim();Code language: C# (cs)

The following example shows how to use the Trim() method to remove the leading and trailing white spaces from the string " Hello, World! ";

using static System.Console;

var message = " Hello, World! ";
var trimmed = message.Trim();

WriteLine(message);
WriteLine(trimmed);Code language: C# (cs)

Output:

 Hello, World!
Hello, World!Code language: C# (cs)

In this example, the message string contains leading and trailing white spaces. We call the Trim() method on the message string. The method returns a result string (trimmed) that has the leading and trailing white spaces removed.

Note that the Trim() method doesn’t change the original string but returns a new string.

The Unicode standard defines white-space characters. The Trim() method removes any leading and trailing characters that, when passed to the Char.IsWhiteSpace() method, returns true:

public static bool IsWhiteSpace (char c);Code language: C# (cs)

Using C# String Trim() to remove the leading and trailing instances of a character

The String Trim() method has an overload that allows you to remove the leading and trailing instances of a character from the current string:

public string Trim (char trimChar);Code language: C# (cs)

In this syntax, the trimChar is a character to remove. The Trim() method returns a new string with the leading and trailing trimChar removed.

For example, the following program uses the Trim() method to remove the leading and trailing asterisk (*) from a string:

using static System.Console;

var message = "***Hello, World!***";
var trimmed = message.Trim('*');

WriteLine(message);
WriteLine(trimmed);Code language: C# (cs)

Output:

***Hello, World!***
Hello, World!Code language: C# (cs)

Using C# String Trim() to remove the leading and trailing occurrences of a set of characters

The String Trim() method has an overload that removes any leading and trailing instances of specified characters from the current string:

public string Trim (
   params char[]? trimChars
);Code language: C# (cs)

In this syntax, the trimChars is an array of characters to remove. Note that if the trimChars is null, the Trim() method returns a new string with the leading and trailing white spaces removed.

The following example uses the Trim() method to remove the leading and trailing characters * and spaces from a string:

using static System.Console;

var message = "*** Hello, World! ***";

char[] trimChars = { '*', ' '};
var trimmed = message.Trim(trimChars);

WriteLine(message);
WriteLine(trimmed);Code language: C# (cs)

Output:

*** Hello, World! ***
Hello, World!Code language: C# (cs)

Summary

Use the C# String Trim() method to remove the leading and trailing white spaces or a set of specified characters from a string.

Was this tutorial helpful ?