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String.Trim Method (Char[])

Removes all leading and trailing occurrences of a set of characters specified in an array from the current String object.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

member Trim : 
        trimChars:char[] -> string

Parameters

trimChars
Type: System.Char[]

An array of Unicode characters to remove, or a null reference (Nothing in Visual Basic).

Return Value

Type: System.String
The string that remains after all occurrences of the characters in the trimChars parameter are removed from the start and end of the current string. If trimChars is a null reference (Nothing in Visual Basic) or an empty array, white-space characters are removed instead.

The Trim method removes from the current string all leading and trailing characters that are in the trimChars parameter. Each leading and trailing trim operation stops when a character that is not in trimChars is encountered. For example, if the current string is "123abc456xyz789" and trimChars contains the digits from "1" through "9", the Trim method returns "abc456xyz".

NoteNote

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

If the current string equals Empty or all the characters in the current instance consist of characters in the trimChars array, the method returns Empty.

If trimChars is a null reference (Nothing in Visual Basic) or an empty array, this method removes any leading or trailing characters that result in the method returning true when they are passed to the Char.IsWhiteSpace method,

Notes to Callers

The .NET Framework 3.5 SP1 and earlier versions maintains an internal list of white-space characters that this method trims if trimChars is a null reference (Nothing in Visual Basic) or an empty array. Starting with the .NET Framework 4, if trimChars is a null reference (Nothing in Visual Basic) or an empty array, the method trims all Unicode white-space characters (that is, characters that produce a true return value when they are passed to the Char.IsWhiteSpace 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).

The following example uses the String.Trim(Char[]) method to remove space, asterisk (*), and apostrophe (') characters from a string.

No code example is currently available or this language may not be supported.

.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

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.

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