String.Compare Method (String, String, StringComparison)
Compares two specified String objects using the specified rules, and returns an integer that indicates their relative position in the sort order.
Assembly: mscorlib (in mscorlib.dll)
static member Compare : strA:string * strB:string * comparisonType:StringComparison -> int
- Type: System.String
The first string to compare.
- Type: System.String
The second string to compare.
- Type: System.StringComparison
One of the enumeration values that specifies the rules to use in the comparison.
Return ValueType: System.Int32
A 32-bit signed integer that indicates the lexical relationship between the two comparands.
Less than zero
strA is less than strB.
strA equals strB.
Greater than zero
strA is greater than strB.
The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the comparands, or use word (culture-sensitive) or ordinal (culture-insensitive) sort rules.
One or both comparands can be a null reference (Nothing in Visual Basic). By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.
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, 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".
Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:Notes to Callers
Character sets include ignorable characters. The method does not consider such characters when it performs a culture-sensitive comparison. To recognize ignorable characters in your comparison, supply a value of StringComparison.Ordinal or OrdinalIgnoreCase for the comparisonType parameter.
.NET FrameworkSupported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
.NET for Windows Phone appsSupported 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.