Compares two specified String objects, ignoring or honoring their case, and using culture-specific information to influence the comparison, and returns an integer that indicates their relative position in the sort order.
Assembly: mscorlib (in mscorlib.dll)
Public Shared Function Compare ( _
strA As String, _
strB As String, _
ignoreCase As Boolean, _
culture As CultureInfo _
) As Integerpublic static int Compare(
string strA,
string strB,
bool ignoreCase,
CultureInfo culture
)public:
static int Compare(
String^ strA,
String^ strB,
bool ignoreCase,
CultureInfo^ culture
)static member Compare :
strA:string *
strB:string *
ignoreCase:bool *
culture:CultureInfo -> int
Parameters
- strA
- Type: System
. . :: . String
The first string to compare.
- strB
- Type: System
. . :: . String
The second string to compare.
- ignoreCase
- Type: System
. . :: . Boolean
true to ignore case during the comparison; otherwise, false.
- culture
- Type: System.Globalization
. . :: . CultureInfo
An object that supplies culture-specific comparison information.
Return Value
Type: SystemA 32-bit signed integer that indicates the lexical relationship between the two comparands.
Value | Condition |
|---|---|
Less than zero | strA is less than strB. |
Zero | strA equals strB. |
Greater than zero | strA is greater than strB. |
| Exception | Condition |
|---|---|
| ArgumentNullException | culture is |
The comparison uses the culture parameter to obtain culture-specific information such as casing rules and the alphabetic order of individual characters. For example, a culture could specify that certain combinations of characters be treated as a single character, or uppercase and lowercase characters be compared in a particular way, or that the sorting order of a character depends on the characters that precede or follow it.
The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization
One or both comparands can be
The comparison terminates when an inequality is discovered or both strings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.
Unexpected results can occur when comparisons are affected by culture-specific casing rules. For example, in Turkish, the following example yields the wrong results because the file system in Turkish does not use linguistic casing rules for the letter "i" in "file".
Shared Function IsFileURI(ByVal path As String) As Boolean
If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
Return True
Else
Return False
End If
End Function
static bool IsFileURI(String path)
{
return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String^ path)
{
return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:
Shared Function IsFileURI(ByVal path As String) As Boolean
If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
Return True
Else
Return False
End If
End Function
static bool IsFileURI(String path)
{
return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String^ path)
{
return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
The following example demonstrates how culture can affect a comparison. In Czech - Czech Republic culture, "ch" is a single character that is greater than "d". However, in English - United States culture, "ch" consists of two characters, and "c" is less than "d".
Imports System
Imports System.Globalization
_
Class Sample
Public Shared Sub Main()
Dim str1 As [String] = "change"
Dim str2 As [String] = "dollar"
Dim relation As [String] = Nothing
relation = symbol([String].Compare(str1, str2, False, New CultureInfo("en-US")))
Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2)
relation = symbol([String].Compare(str1, str2, False, New CultureInfo("cs-CZ")))
Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2)
End Sub 'Main
Private Shared Function symbol(r As Integer) As [String]
Dim s As [String] = "="
If r < 0 Then
s = "<"
Else
If r > 0 Then
s = ">"
End If
End If
Return s
End Function 'symbol
End Class 'Sample
'
'This example produces the following results.
'For en-US: change < dollar
'For cs-CZ: change > dollar
'
using System;
using System.Globalization;
class Sample {
public static void Main() {
String str1 = "change";
String str2 = "dollar";
String relation = null;
relation = symbol( String.Compare(str1, str2, false, new CultureInfo("en-US")) );
Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2);
relation = symbol( String.Compare(str1, str2, false, new CultureInfo("cs-CZ")) );
Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2);
}
private static String symbol(int r) {
String s = "=";
if (r < 0) s = "<";
else if (r > 0) s = ">";
return s;
}
}
/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/
using namespace System;
using namespace System::Globalization;
String^ symbol( int r )
{
String^ s = "=";
if ( r < 0 )
s = "<";
else
if ( r > 0 )
s = ">";
return s;
}
int main()
{
String^ str1 = "change";
String^ str2 = "dollar";
String^ relation = nullptr;
relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "en-US" ) ) );
Console::WriteLine( "For en-US: {0} {1} {2}", str1, relation, str2 );
relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "cs-CZ" ) ) );
Console::WriteLine( "For cs-CZ: {0} {1} {2}", str1, relation, str2 );
}
/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.