System.Globalization.CompareInfo.IsPrefix Method

Determines whether the specified source string starts with the specified prefix using the specified System.Globalization.CompareOptions value.


public virtual bool IsPrefix (string source, string prefix, CompareOptions options)


The string to search in.
The string to compare with the beginning of source.
A value that defines how source and prefix should be compared. options is either the enumeration value CompareOptions.Ordinal, or a bitwise combination of one or more of the following values: CompareOptions.IgnoreCase, CompareOptions.IgnoreSymbols, CompareOptions.IgnoreNonSpace, CompareOptions.IgnoreWidth, and CompareOptions.IgnoreKanaType.


true if the length of prefix is less than or equal to the length of source and source starts with prefix; otherwise, false.


Every string starts and ends with an empty substring (""); therefore, if prefix is an empty string, this method returns true.

The CompareOptions.StringSort value is not valid for this method.


When possible, you should call string comparison methods that have a parameter of type System.Globalization.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.


Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0,,