CompareOptions Enumeration
Defines the string comparison options to use with CompareInfo.
This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.
[Visual Basic] <Flags> <Serializable> Public Enum CompareOptions [C#] [Flags] [Serializable] public enum CompareOptions [C++] [Flags] [Serializable] __value public enum CompareOptions [JScript] public Flags Serializable enum CompareOptions
Remarks
These options denote case sensitivity or whether to ignore types of characters.
The .NET Framework uses three distinct ways of sorting: word sort, string sort, and ordinal sort. Word sort performs a culture-sensitive comparison of strings. Certain nonalphanumeric characters might have special weights assigned to them; for example, the hyphen ("-") might have a very small weight assigned to it so that "coop" and "co-op" appear next to each other in a sorted list. String sort is similar to word sort, except that there are no special cases; therefore, all nonalphanumeric symbols come before all alphanumeric characters. Ordinal sort compares strings based on the Unicode values of each element of the string.
The StringSort value can only be used with CompareInfo.Compare and CompareInfo.GetSortKey. ArgumentException is thrown if the StringSort value is used with CompareInfo.IsPrefix, CompareInfo.IsSuffix, CompareInfo.IndexOf, or CompareInfo.LastIndexOf.
Members
| Member name | Description | Value |
|---|---|---|
| IgnoreCase Supported by the .NET Compact Framework. | Indicates that the string comparison must ignore case. | 1 |
| IgnoreKanaType Supported by the .NET Compact Framework. | Indicates that the string comparison must ignore the Kana type. Kana type refers to Japanese hiragana and katakana characters, which represent phonetic sounds in the Japanese language. Hiragana is used for native Japanese expressions and words, while katakana is used for words borrowed from other languages, such as "computer" or "Internet". A phonetic sound can be expressed in both hiragana and katakana. If this value is selected, the hiragana character for one sound is considered equal to the katakana character for the same sound. | 8 |
| IgnoreNonSpace Supported by the .NET Compact Framework. | Indicates that the string comparison must ignore nonspacing combining characters, such as diacritics. The Unicode Standard defines combining characters as characters that are combined with base characters to produce a new character. Nonspacing combining characters do not occupy a spacing position by themselves when rendered. For more information on nonspacing combining characters, see The Unicode Standard at http://www.unicode.org. | 2 |
| IgnoreSymbols Supported by the .NET Compact Framework. | Indicates that the string comparison must ignore symbols, such as white-space characters, punctuation, currency symbols, the percent sign, mathematical symbols, the ampersand, and so on. | 4 |
| IgnoreWidth Supported by the .NET Compact Framework. | Indicates that the string comparison must ignore the character width. For example, Japanese katakana characters can be written as full-width or half-width and, if this value is selected, the katakana characters written as full-width are considered equal to the same characters written in half-width. | 16 |
| None Supported by the .NET Compact Framework. | Indicates the default option settings for string comparisons. | 0 |
| Ordinal Supported by the .NET Compact Framework. | Indicates that the string comparison must be done using the Unicode values of each character, which is a fast comparison but is culture-insensitive. A string starting with "U+xxxx" comes before a string starting with "U+yyyy", if xxxx is less than yyyy. This flag cannot be combined with other flags and must be used alone. | 1073741824 |
| StringSort Supported by the .NET Compact Framework. | Indicates that the string comparison must use the string sort algorithm, where the hyphen and the apostrophe, as well as other nonalphanumeric symbols, come before alphanumeric characters. | 536870912 |
Example
[Visual Basic, C#, C++] The following code example shows how sorting with StringSort differs from sorting without StringSort.
[Visual Basic] Imports System Imports System.Collections Imports System.Globalization Public Class SamplesCompareOptions Private Class MyStringComparer Implements IComparer Private myComp As CompareInfo Private myOptions As CompareOptions = CompareOptions.None ' Constructs a comparer using the specified CompareOptions. Public Sub New(cmpi As CompareInfo, options As CompareOptions) myComp = cmpi Me.myOptions = options End Sub 'New ' Compares strings with the CompareOptions specified in the constructor. Public Function Compare(a As [Object], b As [Object]) As Integer Implements IComparer.Compare If a = b Then Return 0 End If If a Is Nothing Then Return - 1 End If If b Is Nothing Then Return 1 End If Dim sa As [String] = a Dim sb As [String] = b If Not (sa Is Nothing) And Not (sb Is Nothing) Then Return myComp.Compare(sa, sb, myOptions) End If Throw New ArgumentException("a and b should be strings.") End Function 'Compare End Class 'MyStringComparer Public Shared Sub Main() ' Creates and initializes an array of strings to sort. Dim myArr() As [String] = {"cant", "bill's", "coop", "cannot", "billet", "can't", "con", "bills", "co-op"} Console.WriteLine() Console.WriteLine("Initially,") Dim myStr As [String] For Each myStr In myArr Console.WriteLine(myStr) Next myStr ' Creates and initializes a Comparer to use. 'CultureInfo myCI = new CultureInfo( "en-US", false ); Dim myComp As New MyStringComparer(CompareInfo.GetCompareInfo("en-US"), CompareOptions.None) ' Sorts the array without StringSort. Array.Sort(myArr, myComp) Console.WriteLine() Console.WriteLine("After sorting without CompareOptions.StringSort:") For Each myStr In myArr Console.WriteLine(myStr) Next myStr ' Sorts the array with StringSort. myComp = New MyStringComparer(CompareInfo.GetCompareInfo("en-US"), CompareOptions.StringSort) Array.Sort(myArr, myComp) Console.WriteLine() Console.WriteLine("After sorting with CompareOptions.StringSort:") For Each myStr In myArr Console.WriteLine(myStr) Next myStr End Sub 'Main End Class 'SamplesCompareOptions 'This code produces the following output. ' 'Initially, 'cant 'bill's 'coop 'cannot 'billet 'can't 'con 'bills 'co-op ' 'After sorting without CompareOptions.StringSort: 'billet 'bills 'bill's 'cannot 'cant 'can't 'con 'coop 'co-op ' 'After sorting with CompareOptions.StringSort: 'bill's 'billet 'bills 'can't 'cannot 'cant 'co-op 'con 'coop [C#] using System; using System.Collections; using System.Globalization; public class SamplesCompareOptions { private class MyStringComparer: IComparer { private CompareInfo myComp; private CompareOptions myOptions = CompareOptions.None; // Constructs a comparer using the specified CompareOptions. public MyStringComparer( CompareInfo cmpi, CompareOptions options ) { myComp = cmpi; this.myOptions = options; } // Compares strings with the CompareOptions specified in the constructor. public int Compare(Object a, Object b) { if (a == b) return 0; if (a == null) return -1; if (b == null) return 1; String sa = a as String; String sb = b as String; if (sa != null && sb != null) return myComp.Compare(sa, sb, myOptions); throw new ArgumentException("a and b should be strings."); } } public static void Main() { // Creates and initializes an array of strings to sort. String[] myArr = new String[9] { "cant", "bill's", "coop", "cannot", "billet", "can't", "con", "bills", "co-op" }; Console.WriteLine( "\nInitially," ); foreach ( String myStr in myArr ) Console.WriteLine( myStr ); // Creates and initializes a Comparer to use. //CultureInfo myCI = new CultureInfo( "en-US", false ); MyStringComparer myComp = new MyStringComparer(CompareInfo.GetCompareInfo("en-US"), CompareOptions.None); // Sorts the array without StringSort. Array.Sort( myArr, myComp ); Console.WriteLine( "\nAfter sorting without CompareOptions.StringSort:" ); foreach ( String myStr in myArr ) Console.WriteLine( myStr ); // Sorts the array with StringSort. myComp = new MyStringComparer(CompareInfo.GetCompareInfo("en-US"), CompareOptions.StringSort); Array.Sort( myArr, myComp ); Console.WriteLine( "\nAfter sorting with CompareOptions.StringSort:" ); foreach ( String myStr in myArr ) Console.WriteLine( myStr ); } } /* This code produces the following output. Initially, cant bill's coop cannot billet can't con bills co-op After sorting without CompareOptions.StringSort: billet bills bill's cannot cant can't con coop co-op After sorting with CompareOptions.StringSort: bill's billet bills can't cannot cant co-op con coop */ [C++] #using <mscorlib.dll> using namespace System; using namespace System::Collections; using namespace System::Globalization; // __gc public class SamplesCompareOptions { __gc class MyStringComparer : public IComparer { // Constructs a comparer using the specified CompareOptions. public: CompareInfo * myComp; CompareOptions myOptions; MyStringComparer(CompareInfo* cmpi, CompareOptions options) : myComp(cmpi), myOptions(options) { } // Compares strings with the CompareOptions specified in the constructor. int Compare(Object *a, Object *b) { if (a == b) return 0; if (a == 0) return -1; if (b == 0) return 1; String* sa = dynamic_cast<String*>(a); String* sb = dynamic_cast<String*>(b); if (sa != 0 && sb != 0) return myComp->Compare(sa, sb, myOptions); throw new ArgumentException(S"a and b should be strings."); } }; int main() { // Creates and initializes an array of strings to sort. String* myArr[] = { S"cant", S"bill's", S"coop", S"cannot", S"billet", S"can't", S"con", S"bills", S"co-op" }; Console::WriteLine(S"\nInitially, "); IEnumerator* myEnum = myArr->GetEnumerator(); while (myEnum->MoveNext()) { String* myStr = __try_cast<String*>(myEnum->Current); Console::WriteLine(myStr); } // Creates and initializes a Comparer to use. //CultureInfo* myCI = new CultureInfo(S"en-US", false); MyStringComparer* myComp = new MyStringComparer(CompareInfo::GetCompareInfo(S"en-US"), CompareOptions::None); // Sorts the array without StringSort. Array::Sort(myArr, myComp); Console::WriteLine(S"\nAfter sorting without CompareOptions::StringSort:"); myEnum = myArr->GetEnumerator(); while (myEnum->MoveNext()) { String* myStr = __try_cast<String*>(myEnum->Current); Console::WriteLine(myStr); } // Sorts the array with StringSort. myComp = new MyStringComparer(CompareInfo::GetCompareInfo(S"en-US"), CompareOptions::StringSort); Array::Sort(myArr, myComp); Console::WriteLine(S"\nAfter sorting with CompareOptions::StringSort:"); myEnum = myArr->GetEnumerator(); while (myEnum->MoveNext()) { String* myStr = __try_cast<String*>(myEnum->Current); Console::WriteLine(myStr); } } /* This code produces the following output. Initially, cant bill's coop cannot billet can't con bills co-op After sorting without CompareOptions::StringSort: billet bills bill's cannot cant can't con coop co-op After sorting with CompareOptions::StringSort: bill's billet bills can't cannot cant co-op con coop */
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Requirements
Namespace: System.Globalization
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework
Assembly: Mscorlib (in Mscorlib.dll)