Represents a Unicode character.
(in mscorlib.dll)
Visual Basic (Declaration)
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Structure Char _
Implements IComparable, IConvertible, IComparable(Of Char), _
IEquatable(Of Char)
[SerializableAttribute]
[ComVisibleAttribute(true)]
public struct Char : IComparable, IConvertible,
IComparable<char>, IEquatable<char>
[SerializableAttribute]
[ComVisibleAttribute(true)]
public value class Char : IComparable, IConvertible,
IComparable<wchar_t>, IEquatable<wchar_t>
JScript supports the use of structures, but not the declaration of new ones.
The .NET Framework uses the Char structure to represent a Unicode character. The Unicode Standard identifies each Unicode character with a unique 21-bit scalar number called a code point, and defines the UTF-16 encoding form that specifies how a code point is encoded into a sequence of one or more 16-bit values. Each 16-bit value ranges from hexadecimal 0x0000 through 0xFFFF and is stored in a Char structure. The value of a Char object is its 16-bit numeric (ordinal) value.
A String object is a sequential collection of Char structures that represents a string of text. Most Unicode characters can be represented by a single Char object, but a character that is encoded as a base character, surrogate pair, and/or combining character sequence is represented by multiple Char objects. For this reason, a Char structure in a String object is not necessarily equivalent to a single Unicode character.
For more information about the Unicode Standard, see the Unicode home page.
Functionality
The Char structure provides methods to compare Char objects, convert the value of the current Char object to an object of another type, and determine the Unicode category of a Char object:
Use the CompareTo and Equals methods to compare Char objects.
Use the ConvertFromUtf32 method to convert a code point to a string. Use the ConvertToUtf32 methods to convert a Char object or a surrogate pair of Char objects to a code point.
Use the GetUnicodeCategory methods to get the Unicode category of a character. Use the IsControl, IsDigit, IsHighSurrogate, IsLetter, IsLetterOrDigit, IsLower, IsLowSurrogate, IsNumber, IsPunctuation, IsSeparator, IsSurrogate, IsSurrogatePair, IsSymbol, IsUpper, and IsWhiteSpace methods to determine whether a character is in a particular Unicode category such as digit, letter, punctuation, control character, and so on.
Use the GetNumericValue methods to convert a Char object that represents a number to a numeric value type. Use Parse and TryParse to convert a character in a string into a Char object. Use ToString to convert a Char object to a String object.
Use the ToLower, ToLowerInvariant, ToUpper, and ToUpperInvariant methods to change the case of a Char object.
Interface Implementations
The following code example demonstrates some of the methods in Char.
imports System
Module CharStructure
Public Sub Main()
Dim chA As Char
chA = "A"c
Dim ch1 As Char
ch1 = "1"c
Dim str As String
str = "test string"
Console.WriteLine(chA.CompareTo("B"c)) ' Output: "-1" (meaning 'A' is 1 less than 'B')
Console.WriteLine(chA.Equals("A"c)) ' Output: "True"
Console.WriteLine(Char.GetNumericValue(ch1)) ' Output: "1"
Console.WriteLine(Char.IsControl(Chr(9))) ' Output: "True"
Console.WriteLine(Char.IsDigit(ch1)) ' Output: "True"
Console.WriteLine(Char.IsLetter(","c)) ' Output: "False"
Console.WriteLine(Char.IsLower("u"c)) ' Output: "True"
Console.WriteLine(Char.IsNumber(ch1)) ' Output: "True"
Console.WriteLine(Char.IsPunctuation("."c)) ' Output: "True"
Console.WriteLine(Char.IsSeparator(str, 4)) ' Output: "True"
Console.WriteLine(Char.IsSymbol("+"c)) ' Output: "True"
Console.WriteLine(Char.IsWhiteSpace(str, 4)) ' Output: "True"
Console.WriteLine(Char.Parse("S")) ' Output: "S"
Console.WriteLine(Char.ToLower("M"c)) ' Output: "m"
Console.WriteLine("x"c.ToString()) ' Output: "x"
End Sub
End Module
using System;
public class CharStructureSample {
public static void Main() {
char chA = 'A';
char ch1 = '1';
string str = "test string";
Console.WriteLine(chA.CompareTo('B')); // Output: "-1" (meaning 'A' is 1 less than 'B')
Console.WriteLine(chA.Equals('A')); // Output: "True"
Console.WriteLine(Char.GetNumericValue(ch1)); // Output: "1"
Console.WriteLine(Char.IsControl('\t')); // Output: "True"
Console.WriteLine(Char.IsDigit(ch1)); // Output: "True"
Console.WriteLine(Char.IsLetter(',')); // Output: "False"
Console.WriteLine(Char.IsLower('u')); // Output: "True"
Console.WriteLine(Char.IsNumber(ch1)); // Output: "True"
Console.WriteLine(Char.IsPunctuation('.')); // Output: "True"
Console.WriteLine(Char.IsSeparator(str, 4)); // Output: "True"
Console.WriteLine(Char.IsSymbol('+')); // Output: "True"
Console.WriteLine(Char.IsWhiteSpace(str, 4)); // Output: "True"
Console.WriteLine(Char.Parse("S")); // Output: "S"
Console.WriteLine(Char.ToLower('M')); // Output: "m"
Console.WriteLine('x'.ToString()); // Output: "x"
}
}
using namespace System;
int main()
{
char chA = 'A';
char ch1 = '1';
String^ str = "test string";
Console::WriteLine( chA.CompareTo( 'B' ) ); // Output: "-1" (meaning 'A' is 1 less than 'B')
Console::WriteLine( chA.Equals( 'A' ) ); // Output: "True"
Console::WriteLine( Char::GetNumericValue( ch1 ) ); // Output: "1"
Console::WriteLine( Char::IsControl( '\t' ) ); // Output: "True"
Console::WriteLine( Char::IsDigit( ch1 ) ); // Output: "True"
Console::WriteLine( Char::IsLetter( ',' ) ); // Output: "False"
Console::WriteLine( Char::IsLower( 'u' ) ); // Output: "True"
Console::WriteLine( Char::IsNumber( ch1 ) ); // Output: "True"
Console::WriteLine( Char::IsPunctuation( '.' ) ); // Output: "True"
Console::WriteLine( Char::IsSeparator( str, 4 ) ); // Output: "True"
Console::WriteLine( Char::IsSymbol( '+' ) ); // Output: "True"
Console::WriteLine( Char::IsWhiteSpace( str, 4 ) ); // Output: "True"
Console::WriteLine( Char::Parse( "S" ) ); // Output: "S"
Console::WriteLine( Char::ToLower( 'M' ) ); // Output: "m"
Console::WriteLine( 'x' ); // Output: "x"
}
All members of this type are thread safe. Members that appear to modify instance state actually return a new instance initialized with the new value. As with any other type, reading and writing to a shared variable that contains an instance of this type must be protected by a lock to guarantee thread safety.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference