CompareInfo::IsPrefix Method (String^, String^)
Determines whether the specified source string starts with the specified prefix.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- source
-
Type:
System::String^
The string to search in.
- prefix
-
Type:
System::String^
The string to compare with the beginning of source.
Return Value
Type: System::Booleantrue if the length of prefix is less than or equal to the length of source and source starts with prefix; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentNullException | source is null. -or- prefix is null. |
Every string starts and ends with an empty substring (""); therefore, if prefix is an empty string, this method returns true.
Note |
|---|
When possible, you should call string comparison methods that have a parameter of type CompareOptions to specify the kind of comparison expected. As a general rule, use linguistic options (using the current culture) for comparing strings displayed in the user interface and specify CompareOptions::Ordinal or CompareOptions::OrdinalIgnoreCase for security comparisons. |
The following example determines whether a string is the prefix or suffix of another string.
using namespace System; using namespace System::Globalization; int main() { // Defines the strings to compare. String^ myStr1 = "calle"; String^ myStr2 = "llegar"; String^ myXfix = "lle"; // Uses the CompareInfo property of the InvariantCulture. CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo; // Determines whether myXfix is a prefix of S"calle" and S"llegar". Console::WriteLine( "IsPrefix( {0}, {1}) : {2}", myStr1, myXfix, myComp->IsPrefix( myStr1, myXfix ) ); Console::WriteLine( "IsPrefix( {0}, {1}) : {2}", myStr2, myXfix, myComp->IsPrefix( myStr2, myXfix ) ); // Determines whether myXfix is a suffix of S"calle" and S"llegar". Console::WriteLine( "IsSuffix( {0}, {1}) : {2}", myStr1, myXfix, myComp->IsSuffix( myStr1, myXfix ) ); Console::WriteLine( "IsSuffix( {0}, {1}) : {2}", myStr2, myXfix, myComp->IsSuffix( myStr2, myXfix ) ); } /* This code produces the following output. IsPrefix(calle, lle) : False IsPrefix(llegar, lle) : True IsSuffix(calle, lle) : True IsSuffix(llegar, lle) : False */
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
