.NET Framework Class Library
StringTrim Method

Removes all leading and trailing white-space characters from the current String object.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Public Function Trim As [%$TOPIC/t97s7bs3_en-us_VS_110_2_0_0_0_0%]
public [%$TOPIC/t97s7bs3_en-us_VS_110_2_0_1_0_0%] Trim()
public:
[%$TOPIC/t97s7bs3_en-us_VS_110_2_0_2_0_0%]^ Trim()
member Trim : unit -> [%$TOPIC/t97s7bs3_en-us_VS_110_2_0_3_0_0%]

Return Value

Type: SystemString
The string that remains after all white-space characters are removed from the start and end of the current string.
Remarks

The Trim method removes from the current string all leading and trailing white-space characters. Each leading and trailing trim operation stops when a non-white-space character is encountered. For example, if the current string is "   abc   xyz   ", the Trim method returns "abc   xyz".

NoteNote

This method does not modify the value of the current instance. Instead, it returns a new string in which all leading and trailing white space characters found in the current instance are removed.

If the current string equals Empty or all the characters in the current instance consist of white-space characters, the method returns Empty.

White-space characters are defined by the Unicode standard. The Trim method removes any leading and trailing characters that produce a return value of true when they are passed to the CharIsWhiteSpace method.

Notes to Callers

The .NET Framework 3.5 SP1 and earlier versions maintain an internal list of white-space characters that this method trims. Starting with the .NET Framework 4, the method trims all Unicode white-space characters (that is, characters that produce a true return value when they are passed to the CharIsWhiteSpace method). Because of this change, the Trim method in the .NET Framework 3.5 SP1 and earlier versions removes two characters, ZERO WIDTH SPACE (U+200B) and ZERO WIDTH NO-BREAK SPACE (U+FEFF), that the Trim method in the .NET Framework 4 and later versions does not remove. In addition, the Trim method in the .NET Framework 3.5 SP1 and earlier versions does not trim three Unicode white-space characters: MONGOLIAN VOWEL SEPARATOR (U+180E), NARROW NO-BREAK SPACE (U+202F), and MEDIUM MATHEMATICAL SPACE (U+205F).

Examples

The following example uses the StringTrim method to remove any extra white space from strings entered by the user before concatenating them.

Module Example
   Public Sub Main()
      Console.Write("Enter your first name: ")
      Dim firstName As String = Console.ReadLine()

      Console.Write("Enter your middle name or initial: ")
      Dim middleName As String = Console.ReadLine()

      Console.Write("Enter your last name: ")
      Dim lastName As String = Console.ReadLine

      Console.WriteLine()
      Console.WriteLine("You entered '{0}', '{1}', and '{2}'.", _
                        firstName, middleName, lastName)

      Dim name As String = ((firstName.Trim() + " " + middleName.Trim()).Trim() _
                           + " " + lastName.Trim()).Trim()                        
      Console.WriteLine("The result is " + name + ".")
   End Sub 
End Module 
' The following is possible output from this example: 
'       Enter your first name:    John 
'       Enter your middle name or initial: 
'       Enter your last name:    Doe 
'        
'       You entered '   John  ', '', and '   Doe'. 
'       The result is John Doe
using System;

public class Example
{
   public static void Main()
   {
      Console.Write("Enter your first name: ");
      string firstName = Console.ReadLine();

      Console.Write("Enter your middle name or initial: ");
      string middleName = Console.ReadLine();

      Console.Write("Enter your last name: ");
      string lastName = Console.ReadLine();

      Console.WriteLine();
      Console.WriteLine("You entered '{0}', '{1}', and '{2}'.", 
                        firstName, middleName, lastName);

      string name = ((firstName.Trim() + " " + middleName.Trim()).Trim() + " " + 
                    lastName.Trim()).Trim();
      Console.WriteLine("The result is " + name + ".");
   }
}
// The following is possible output from this example: 
//       Enter your first name:    John 
//       Enter your middle name or initial: 
//       Enter your last name:    Doe 
//        
//       You entered '   John  ', '', and '   Doe'. 
//       The result is John Doe
Version Information

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1
Platforms

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.