String::Compare Method (String, Int32, String, Int32, Int32, StringComparison)
Compares substrings of 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)
public: static int Compare( String^ strA, int indexA, String^ strB, int indexB, int length, StringComparison comparisonType )
Parameters
- strA
- Type: System::String
The first string to use in the comparison.
- indexA
- Type: System::Int32
The position of the substring within strA.
- strB
- Type: System::String
The second string to use in the comparison.
- indexB
- Type: System::Int32
The position of the substring within strB.
- length
- Type: System::Int32
The maximum number of characters in the substrings to compare.
- comparisonType
- Type: System::StringComparison
One of the enumeration values that specifies the rules to use in the comparison.
Return Value
Type: System::Int32A 32-bit signed integer that indicates the lexical relationship between the two comparands.
Value | Condition |
|---|---|
Less than zero | The substring in the strA parameter is less than the substring in the strB parameter. |
Zero | The substrings are equal, or the length parameter is zero. |
Greater than zero | The substring in strA is greater than the substring in strB. |
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | indexA is greater than strA.Length. -or- indexB is greater than strB.Length. -or- indexA, indexB, or length is negative. -or- Either indexA or indexB is nullptr, and length is greater than zero. |
| ArgumentException | comparisonType is not a StringComparison value. |
The substrings to compare start in strA at indexA and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero, not position one. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.
The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.
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 nullptr. 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 substrings 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:
The following example compares two substrings.
// Sample for String::Compare(String, Int32, String, Int32, Int32) using namespace System; int main() { // 0123456 String^ str1 = "machine"; String^ str2 = "device"; String^ str; int result; Console::WriteLine(); Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 ); result = String::Compare( str1, 2, str2, 0, 2 ); str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to")); Console::Write( "Substring '{0}' in ' {1}' is ", str1->Substring( 2, 2 ), str1 ); Console::Write( " {0} ", str ); Console::WriteLine( "substring '{0}' in ' {1}'.", str2->Substring( 0, 2 ), str2 ); } /* This example produces the following results: str1 = 'machine', str2 = 'device' Substring 'ch' in 'machine' is less than substring 'de' in 'device'. */
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.