How to: Search Strings Using String Methods (C# Programming Guide)

The string type, which is an alias for the System.String class, provides a number of useful methods for searching the contents of a string.

Example

The following example uses the IndexOf, LastIndexOf, StartsWith, and EndsWith methods to search the strings.

class StringSearch
{
 static void Main()
 {
 string str = "Extension methods have all the capabilities of regular static methods.";
 // Write the string and include the quotation marks.
 System.Console.WriteLine("\"{0}\"", str);
 // Simple comparisons are always case sensitive!
 bool test1 = str.StartsWith("extension");
 System.Console.WriteLine("Starts with \"extension\"? {0}", test1);
 // For user input and strings that will be displayed to the end user, 
 // use the StringComparison parameter on methods that have it to specify how to match strings.
 bool test2 = str.StartsWith("extension", System.StringComparison.CurrentCultureIgnoreCase);
 System.Console.WriteLine("Starts with \"extension\"? {0} (ignoring case)", test2);
 bool test3 = str.EndsWith(".", System.StringComparison.CurrentCultureIgnoreCase);
 System.Console.WriteLine("Ends with '.'? {0}", test3);
 // This search returns the substring between two strings, so 
 // the first index is moved to the character just after the first string.
 int first = str.IndexOf("methods") + "methods".Length;
 int last = str.LastIndexOf("methods");
 string str2 = str.Substring(first, last - first);
 System.Console.WriteLine("Substring between \"methods\" and \"methods\": '{0}'", str2);
 // Keep the console window open in debug mode
 System.Console.WriteLine("Press any key to exit.");
 System.Console.ReadKey();
 }
}
/*
Output:
"Extension methods have all the capabilities of regular static methods."
Starts with "extension"? False
Starts with "extension"? True (ignoring case)
Ends with '.'? True
Substring between "methods" and "methods": ' have all the capabilities of regular static '
Press any key to exit. 
*/

See Also

Tasks

How to: Search Strings Using Regular Expressions (C# Programming Guide)

Concepts

C# Programming Guide

LINQ and Strings

Other Resources

Strings (C# Programming Guide)