String.StartsWith Method (String)
Determines whether the beginning of this string instance matches the specified string.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System.String
The string to compare.
Return Value
Type: System.Booleantrue if value matches the beginning of this string; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentNullException | value is null. |
This method compares value to the substring at the beginning of this instance that is the same length as value, and returns an indication whether they are equal. To be equal, value must be an empty string (String.Empty), must be a reference to this same instance, or must match the beginning of this instance.
This method performs a word (case-sensitive and culture-sensitive) comparison using the current culture.
Notes to CallersAs explained in Best Practices for Using Strings in the .NET Framework, we recommend that you avoid calling string comparison methods that substitute default values and instead call methods that require parameters to be explicitly specified. To determine whether a string begins with a particular substring by using the string comparison rules of the current culture, call the StartsWith(String, StringComparison) method overload with a value of StringComparison.CurrentCulture for its comparisonType parameter.
The following example demonstrates how you can use the StartsWith method.
using System; public class EndsWithTest { public static void Main() { // process a string that contains html tags // this sample does not remove embedded tags (tags in the middle of a line) string [] strSource = { "<b>This is bold text</b>", "<H1>This is large Text</H1>", "<b><i><font color=green>This has multiple tags</font></i></b>", "<b>This has <i>embedded</i> tags.</b>", "<This line simply begins with a lesser than symbol, it should not be modified" }; Console.WriteLine("The following lists the items before the tags have been stripped:"); Console.WriteLine("-----------------------------------------------------------------"); // print out the initial array of strings foreach ( string s in strSource ) Console.WriteLine( s ); Console.WriteLine(); Console.WriteLine("The following lists the items after the tags have been stripped:"); Console.WriteLine("----------------------------------------------------------------"); // print out the array of strings foreach ( string s in strSource ) Console.WriteLine( StripStartTags( s ) ); } private static string StripStartTags( string item ) { // try to find a tag at the start of the line using StartsWith if (item.Trim().StartsWith("<")) { // now search for the closing tag... int lastLocation = item.IndexOf( ">" ); // remove the identified section, if it is a valid region if ( lastLocation >= 0 ) item = item.Substring( lastLocation + 1 ); } return item; } }
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.