CompareInfo Class
Implements a set of methods for culture-sensitive string comparisons.
Assembly: mscorlib (in mscorlib.dll)
The CompareInfo type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() ![]() | Compare(String, String) | Compares two strings. |
![]() ![]() ![]() | Compare(String, String, CompareOptions) | Compares two strings using the specified CompareOptions value. |
![]() ![]() ![]() | Compare(String, Int32, String, Int32) | Compares the end section of a string with the end section of another string. |
![]() ![]() ![]() | Compare(String, Int32, String, Int32, CompareOptions) | Compares the end section of a string with the end section of another string using the specified CompareOptions value. |
![]() ![]() ![]() | Compare(String, Int32, Int32, String, Int32, Int32) | Compares a section of one string with a section of another string. |
![]() ![]() ![]() | Compare(String, Int32, Int32, String, Int32, Int32, CompareOptions) | Compares a section of one string with a section of another string using the specified CompareOptions value. |
![]() ![]() ![]() | Equals | Determines whether the specified object is equal to the current CompareInfo object. (Overrides Object::Equals(Object).) |
![]() ![]() ![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() ![]() ![]() | GetCompareInfo(Int32) | Initializes a new CompareInfo object that is associated with the culture with the specified identifier. |
![]() ![]() | GetCompareInfo(String) | Initializes a new CompareInfo object that is associated with the culture with the specified name. |
![]() ![]() | GetCompareInfo(Int32, Assembly) | Initializes a new CompareInfo object that is associated with the specified culture and that uses string comparison methods in the specified Assembly. |
![]() ![]() | GetCompareInfo(String, Assembly) | Initializes a new CompareInfo object that is associated with the specified culture and that uses string comparison methods in the specified Assembly. |
![]() ![]() ![]() | GetHashCode | Serves as a hash function for the current CompareInfo for hashing algorithms and data structures, such as a hash table. (Overrides Object::GetHashCode().) |
![]() | GetSortKey(String) | Gets the sort key for the specified string. |
![]() | GetSortKey(String, CompareOptions) | Gets a SortKey object for the specified string using the specified CompareOptions value. |
![]() ![]() ![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() ![]() ![]() | IndexOf(String, Char) | Searches for the specified character and returns the zero-based index of the first occurrence within the entire source string. |
![]() ![]() ![]() | IndexOf(String, String) | Searches for the specified substring and returns the zero-based index of the first occurrence within the entire source string. |
![]() ![]() ![]() | IndexOf(String, Char, CompareOptions) | Searches for the specified character and returns the zero-based index of the first occurrence within the entire source string using the specified CompareOptions value. |
![]() | IndexOf(String, Char, Int32) | Searches for the specified character and returns the zero-based index of the first occurrence within the section of the source string that extends from the specified index to the end of the string. |
![]() ![]() ![]() | IndexOf(String, String, CompareOptions) | Searches for the specified substring and returns the zero-based index of the first occurrence within the entire source string using the specified CompareOptions value. |
![]() | IndexOf(String, String, Int32) | Searches for the specified substring and returns the zero-based index of the first occurrence within the section of the source string that extends from the specified index to the end of the string. |
![]() ![]() ![]() | IndexOf(String, Char, Int32, CompareOptions) | Searches for the specified character and returns the zero-based index of the first occurrence within the section of the source string that extends from the specified index to the end of the string using the specified CompareOptions value. |
![]() ![]() ![]() | IndexOf(String, Char, Int32, Int32) | Searches for the specified character and returns the zero-based index of the first occurrence within the section of the source string that starts at the specified index and contains the specified number of elements. |
![]() ![]() ![]() | IndexOf(String, String, Int32, CompareOptions) | Searches for the specified substring and returns the zero-based index of the first occurrence within the section of the source string that extends from the specified index to the end of the string using the specified CompareOptions value. |
![]() ![]() ![]() | IndexOf(String, String, Int32, Int32) | Searches for the specified substring and returns the zero-based index of the first occurrence within the section of the source string that starts at the specified index and contains the specified number of elements. |
![]() ![]() ![]() | IndexOf(String, Char, Int32, Int32, CompareOptions) | Searches for the specified character and returns the zero-based index of the first occurrence within the section of the source string that starts at the specified index and contains the specified number of elements using the specified CompareOptions value. |
![]() ![]() ![]() | IndexOf(String, String, Int32, Int32, CompareOptions) | Searches for the specified substring and returns the zero-based index of the first occurrence within the section of the source string that starts at the specified index and contains the specified number of elements using the specified CompareOptions value. |
![]() ![]() ![]() | IsPrefix(String, String) | Determines whether the specified source string starts with the specified prefix. |
![]() ![]() ![]() | IsPrefix(String, String, CompareOptions) | Determines whether the specified source string starts with the specified prefix using the specified CompareOptions value. |
![]() ![]() | IsSortable(Char) | Indicates whether a specified Unicode character is sortable. |
![]() ![]() | IsSortable(String) | Indicates whether a specified Unicode string is sortable. |
![]() ![]() ![]() | IsSuffix(String, String) | Determines whether the specified source string ends with the specified suffix. |
![]() ![]() ![]() | IsSuffix(String, String, CompareOptions) | Determines whether the specified source string ends with the specified suffix using the specified CompareOptions value. |
![]() ![]() ![]() | LastIndexOf(String, Char) | Searches for the specified character and returns the zero-based index of the last occurrence within the entire source string. |
![]() ![]() ![]() | LastIndexOf(String, String) | Searches for the specified substring and returns the zero-based index of the last occurrence within the entire source string. |
![]() ![]() ![]() | LastIndexOf(String, Char, CompareOptions) | Searches for the specified character and returns the zero-based index of the last occurrence within the entire source string using the specified CompareOptions value. |
![]() | LastIndexOf(String, Char, Int32) | Searches for the specified character and returns the zero-based index of the last occurrence within the section of the source string that extends from the beginning of the string to the specified index. |
![]() ![]() ![]() | LastIndexOf(String, String, CompareOptions) | Searches for the specified substring and returns the zero-based index of the last occurrence within the entire source string using the specified CompareOptions value. |
![]() | LastIndexOf(String, String, Int32) | Searches for the specified substring and returns the zero-based index of the last occurrence within the section of the source string that extends from the beginning of the string to the specified index. |
![]() ![]() ![]() | LastIndexOf(String, Char, Int32, CompareOptions) | Searches for the specified character and returns the zero-based index of the last occurrence within the section of the source string that extends from the beginning of the string to the specified index using the specified CompareOptions value. |
![]() ![]() ![]() | LastIndexOf(String, Char, Int32, Int32) | Searches for the specified character and returns the zero-based index of the last occurrence within the section of the source string that contains the specified number of elements and ends at the specified index. |
![]() ![]() ![]() | LastIndexOf(String, String, Int32, CompareOptions) | Searches for the specified substring and returns the zero-based index of the last occurrence within the section of the source string that extends from the beginning of the string to the specified index using the specified CompareOptions value. |
![]() ![]() ![]() | LastIndexOf(String, String, Int32, Int32) | Searches for the specified substring and returns the zero-based index of the last occurrence within the section of the source string that contains the specified number of elements and ends at the specified index. |
![]() ![]() ![]() | LastIndexOf(String, Char, Int32, Int32, CompareOptions) | Searches for the specified character and returns the zero-based index of the last occurrence within the section of the source string that contains the specified number of elements and ends at the specified index using the specified CompareOptions value. |
![]() ![]() ![]() | LastIndexOf(String, String, Int32, Int32, CompareOptions) | Searches for the specified substring and returns the zero-based index of the last occurrence within the section of the source string that contains the specified number of elements and ends at the specified index using the specified CompareOptions value. |
![]() ![]() ![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() ![]() ![]() | ToString | Returns a string that represents the current CompareInfo. (Overrides Object::ToString().) |
| Name | Description | |
|---|---|---|
![]() ![]() | IDeserializationCallback::OnDeserialization | Runs when the entire object graph has been deserialized. |
The CultureInfo class includes a CompareInfo property that is an instance of this class. String::Compare uses the information in CultureInfo::CompareInfo to compare strings.
CompareInfo provides the GetCompareInfo method, instead of public constructors, to allow for late-bound access.
To create a CompareInfo object for any culture, the application should use the CultureInfo::CompareInfo property, or use the GetCompareInfo method.
Ignored Search Values
Comparison operations, such as those performed by the IndexOf or LastIndexOf methods, can yield unexpected results if the value to search for is ignored. The search value is ignored if it is an empty string (""), a character or string consisting of characters having code points that are not considered in the operation because of comparison options, or a value with code points that have no linguistic significance. If the search value for the IndexOf method is an empty string, for example, the return value is zero.
Security Considerations
If a security decision depends on a string comparison or a case change, the application should use the InvariantCulture to ensure that the behavior is consistent, regardless of the culture settings of the operating system.
Note When possible, the application should use string comparison methods that accept a CompareOptions value to specify the kind of comparison expected. As a general rule, user-facing comparisons are best served by the use of linguistic options (using the current culture), while security comparisons should specify Ordinal or OrdinalIgnoreCase.
The following code example shows how the CompareInfo object associated with a CultureInfo object affects string comparison.
using namespace System; using namespace System::Text; using namespace System::Globalization; int main() { array<String^>^ sign = gcnew array<String^> { "<", "=", ">" }; // The code below demonstrates how strings compare // differently for different cultures. String^ s1 = "Coté"; String^ s2 = "coté"; String^ s3 = "côte"; // Set sort order of strings for French in France. CompareInfo^ ci = (gcnew CultureInfo("fr-FR"))->CompareInfo; Console::WriteLine(L"The LCID for {0} is {1}.", ci->Name, ci->LCID); // Display the result using fr-FR Compare of Coté = coté. Console::WriteLine(L"fr-FR Compare: {0} {2} {1}", s1, s2, sign[ci->Compare(s1, s2, CompareOptions::IgnoreCase) + 1]); // Display the result using fr-FR Compare of coté > côte. Console::WriteLine(L"fr-FR Compare: {0} {2} {1}", s2, s3, sign[ci->Compare(s2, s3, CompareOptions::None) + 1]); // Set sort order of strings for Japanese as spoken in Japan. ci = (gcnew CultureInfo("ja-JP"))->CompareInfo; Console::WriteLine(L"The LCID for {0} is {1}.", ci->Name, ci->LCID); // Display the result using ja-JP Compare of coté < côte. Console::WriteLine("ja-JP Compare: {0} {2} {1}", s2, s3, sign[ci->Compare(s2, s3) + 1]); } // This code produces the following output. // // The LCID for fr-FR is 1036. // fr-FR Compare: Coté = coté // fr-FR Compare: coté > côte // The LCID for ja-JP is 1041. // ja-JP Compare: coté < côte
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.







