StartsWith Method

Determines whether the beginning of this instance matches the specified String.

[Visual Basic]
Public Function StartsWith( _
   ByVal value As String _
) As Boolean
[C#]
public bool StartsWith(
   string value
);
[C++]
public: bool StartsWith(
   String* value
);
[JScript]
public function StartsWith(
   value : String
) : Boolean;

Parameters

value: The String to seek.

Return Value

true if value matches the beginning of this string or is Empty; otherwise false.

Exceptions

Exception Type	Condition
ArgumentNullException	value is a null reference (Nothing in Visual Basic).

Remarks

This method makes a comparison at the beginning of the string, determines whether it matches this current instance, and returns a Boolean representation of their relationship. The specified string must match the prefix or be an empty string (that is, equals Empty).

This method performs a word (case-sensitive and culture-sensitive) search using the current culture.

Example

The following code example demonstrates how you can use the StartsWith method.

[Visual Basic] 
Imports System

Public Class EndsWithTest

    Public Shared Sub Main()
        Dim strSource As String() = {"<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"}

        ' process a string that contains html tags
        ' this sample does not remove embedded tags (tags in the middle of a line)

        Console.WriteLine("The following lists the items before the ends have been stripped:")
        Console.WriteLine("-----------------------------------------------------------------")

        ' print out the initial array of strings
        Dim s As String
        For Each s In  strSource
            Console.WriteLine(s)
        Next s

        Console.WriteLine()

        Console.WriteLine("The following lists the items after the ends have been stripped:")
        Console.WriteLine("----------------------------------------------------------------")

        ' print out the array of strings
        For Each s In  strSource
            Console.WriteLine(StripStartTags(s))
        Next s

    End Sub 'Main

    Private Shared Function StripStartTags(item As String) As String

        ' try to find a tag at the start of the line using StartsWith
        If item.Trim().StartsWith("<") Then

            ' now search for the closing tag...
           Dim lastLocation As Integer = item.IndexOf(">")

            If lastLocation >= 0 Then
                ' remove the identified section, if it is a valid region
                item = item.Substring((lastLocation + 1))
            End If
        End If

        Return item

    End Function 'StripStartTags

End Class 'EndsWithTest

[C#] 
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 ends 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 ends 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;
    }
}

[C++] 
#using <mscorlib.dll>

using namespace System;
using namespace System::Collections;

String* StripStartTags(String* item)
{
   // try to find a tag at the start of the line using StartsWith
   if (item->Trim()->StartsWith(S"<")) {

      // now search for the closing tag->->.
      int lastLocation = item->IndexOf(S">");

      // remove the identified section, if it is a valid region
      if (lastLocation >= 0)
         item =  item->Substring(lastLocation + 1);
   }
   return item;
}

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[] = { S"<b>This is bold text</b>", S"<H1>This is large Text</H1>",
      S"<b><i><font color=green>This has multiple tags</font></i></b>",
      S"<b>This has <i>embedded</i> tags.</b>",
      S"<This line simply begins with a lesser than symbol, it should not be modified" };

   Console::WriteLine(S"The following lists the items before the ends have been stripped:");
   Console::WriteLine(S"-----------------------------------------------------------------");

   // print [Out] the* initial array of strings
   IEnumerator* myEnum1 = strSource->GetEnumerator();
   while (myEnum1->MoveNext()) {
      String* s = __try_cast<String*>(myEnum1->Current);

      Console::WriteLine(s);
   }
   Console::WriteLine();

   Console::WriteLine(S"The following lists the items after the ends have been stripped:");
   Console::WriteLine(S"----------------------------------------------------------------");

   // print [Out] the* array of strings
   IEnumerator* myEnum2 = strSource->GetEnumerator();
   while (myEnum2->MoveNext()) {
      String* s = __try_cast<String*>(myEnum2->Current);

      Console::WriteLine(StripStartTags(s));
   }

}

[JScript] 
import System;

public class EndsWithTest {
    public static function Main() : void {

        // process a string that contains html tags
        // this sample does not remove embedded tags (tags in the middle of a line)

        var strSource : String [] = [ "<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 ends have been stripped:");
        Console.WriteLine("-----------------------------------------------------------------");

        // print out the initial array of strings
        for( var i : int in strSource )
            Console.WriteLine( strSource[i] );

        Console.WriteLine();

        Console.WriteLine("The following lists the items after the ends have been stripped:");
        Console.WriteLine("----------------------------------------------------------------");

        // print out the array of strings
        for ( i in strSource )
            Console.WriteLine( StripStartTags( strSource[i] ) );
    }

    private static function StripStartTags( item : String ) : String  {

        // try to find a tag at the start of the line using StartsWith
        if (item.Trim().StartsWith("<")) {

            // now search for the closing tag...
            var lastLocation : int = item.IndexOf( ">" );

            // remove the identified section, if it is a valid region
            if ( lastLocation >= 0 )
                item =  item.Substring( lastLocation + 1 );
        }

        return item;
    }
}
EndsWithTest.Main();

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework - Windows CE .NET, Common Language Infrastructure (CLI) Standard