CompareOptions Enumeration
This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.
Namespace: System.GlobalizationAssembly: mscorlib (in mscorlib.dll)
'Declaration <SerializableAttribute> _ <ComVisibleAttribute(True)> _ <FlagsAttribute> _ Public Enumeration CompareOptions 'Usage Dim instance As CompareOptions
/** @attribute SerializableAttribute() */ /** @attribute ComVisibleAttribute(true) */ /** @attribute FlagsAttribute() */ public enum CompareOptions
SerializableAttribute ComVisibleAttribute(true) FlagsAttribute public enum CompareOptions
| Member name | Description | |
|---|---|---|
![]() | IgnoreCase | Indicates that the string comparison must ignore case. |
![]() | IgnoreKanaType | 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. |
![]() | IgnoreNonSpace | 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. |
![]() | IgnoreSymbols | 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. |
![]() | IgnoreWidth | 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. |
![]() | None | Indicates the default option settings for string comparisons. |
![]() | Ordinal | 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. |
![]() | OrdinalIgnoreCase | Indicates that the string comparison must ignore case, then perform an ordinal comparison. This is equivalent to converting the string to uppercase using the invariant culture and then performing an ordinal comparison on the result. |
![]() | StringSort | 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. |
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.
The following code example shows how sorting with StringSort differs from sorting without StringSort.
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
import System.* ;
import System.Collections.* ;
import System.Globalization.* ;
public class SamplesCompareOptions
{
private class MyStringComparer implements 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;
} //MyStringComparer
// 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 =(String) a;
String sb = (String)b;
if (sa != null && sb != null) {
return myComp.Compare(sa, sb, myOptions);
}
throw new ArgumentException("a and b should be strings.");
} //Compare
} //MyStringComparer
public static void main(String[] args)
{
// Creates and initializes an array of strings to sort.
String myArr[] = new String[]{"cant", "bill's", "coop", "cannot",
"billet", "can't", "con", "bills", "co-op"};
Console.WriteLine("\nInitially,");
SamplesCompareOptions mySamplesCompareOptions =
new SamplesCompareOptions();
for(int i=0 ; i < myArr.length ;i++) {
String myStr = myArr[i];
Console.WriteLine(myStr);
}
// Creates and initializes a Comparer to use.
//CultureInfo myCI = new CultureInfo( "en-US", false );
MyStringComparer myComp = mySamplesCompareOptions.new MyStringComparer(
CompareInfo.GetCompareInfo("en-US"), CompareOptions.None);
// Sorts the array without StringSort.
Array.Sort(myArr, myComp);
Console.WriteLine("\nAfter sorting without CompareOptions.StringSort:");
for(int i=0; i< myArr.length ;i++) {
String myStr = myArr[i];
Console.WriteLine(myStr);
}
// Sorts the array with StringSort.
myComp = mySamplesCompareOptions.new MyStringComparer(
CompareInfo.GetCompareInfo("en-US"), CompareOptions.StringSort);
Array.Sort(myArr, myComp);
Console.WriteLine("\nAfter sorting with CompareOptions.StringSort:");
for(int i=0; i< myArr.length ;i++) {
String myStr = myArr[i];
Console.WriteLine(myStr);
}
} //main
} //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
*/
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
