String.LastIndexOfAny Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array. The method returns -1 if the characters in the array are not found in this instance.

Overloads

LastIndexOfAny(Char[])	Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array.
LastIndexOfAny(Char[], Int32)	Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array. The search starts at a specified character position and proceeds backward toward the beginning of the string.
LastIndexOfAny(Char[], Int32, Int32)	Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array. The search starts at a specified character position and proceeds backward toward the beginning of the string for a specified number of character positions.

LastIndexOfAny(Char[])

Source:

String.Searching.cs

Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array.

public:
 int LastIndexOfAny(cli::array <char> ^ anyOf);

public int LastIndexOfAny (char[] anyOf);

member this.LastIndexOfAny : char[] -> int

Public Function LastIndexOfAny (anyOf As Char()) As Integer

Parameters

anyOf

Char[]

A Unicode character array containing one or more characters to seek.

Returns

Int32

The index position of the last occurrence in this instance where any character in anyOf was found; -1 if no character in anyOf was found.

Exceptions

ArgumentNullException

anyOf is null.

Examples

The following example finds the index of the last occurrence of any character in the string "is" within another string.

// Sample for String::LastIndexOfAny(Char[])
using namespace System;
int main()
{
   String^ br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
   String^ br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
   String^ str = "Now is the time for all good men to come to the aid of their party.";
   int start;
   int at;
   String^ target = "is";
   array<Char>^anyOf = target->ToCharArray();
   start = str->Length - 1;
   Console::WriteLine( "The last character occurrence  from position {0} to 0.", start );
   Console::WriteLine( "{1}{0}{2}{0}{3}{0}", Environment::NewLine, br1, br2, str );
   Console::Write( "A character in '{0}' occurs at position: ", target );
   at = str->LastIndexOfAny( anyOf );
   if ( at > -1 )
      Console::Write( at );
   else
      Console::Write( "(not found)" );

   Console::Write( "{0}{0}{0}", Environment::NewLine );
}

/*
This example produces the following results:
The last character occurrence  from position 66 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 58


*/

// Sample for String.LastIndexOfAny(Char[])
using System;

class Sample {
    public static void Main() {

    string br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
    string br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
    string str = "Now is the time for all good men to come to the aid of their party.";
    int start;
    int at;
    string target = "is";
    char[] anyOf = target.ToCharArray();

    start = str.Length-1;
    Console.WriteLine("The last character occurrence  from position {0} to 0.", start);
    Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str);
    Console.Write("A character in '{0}' occurs at position: ", target);

    at = str.LastIndexOfAny(anyOf);
    if (at > -1)
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.Write("{0}{0}{0}", Environment.NewLine);
    }
}
/*
This example produces the following results:
The last character occurrence  from position 66 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 58


*/

// Sample for String.LastIndexOfAny(Char[])
open System

let br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
let br2 = "0123456789012345678901234567890123456789012345678901234567890123456"
let str = "Now is the time for all good men to come to the aid of their party."
let target = "is"
let anyOf = target.ToCharArray()

let start = str.Length - 1
printfn $"The last character occurrence  from position {start} to 0."
printfn $"{br1}{Environment.NewLine}{br2}{Environment.NewLine}{str}{Environment.NewLine}"
printf $"A character in '{target}' occurs at position: "

let at = str.LastIndexOfAny anyOf
if at > -1 then
    printf $"{at}"
else
    printf "(not found)"
printf $"{Environment.NewLine}{Environment.NewLine}{Environment.NewLine}"
(*
This example produces the following results:
The last character occurrence  from position 66 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 58


*)

' Sample for String.LastIndexOfAny(Char[])
 _

Class Sample
   
   Public Shared Sub Main()
      
      Dim br1 As String = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
      Dim br2 As String = "0123456789012345678901234567890123456789012345678901234567890123456"
      Dim str As String = "Now is the time for all good men to come to the aid of their party."
      Dim start As Integer
      Dim at As Integer
      Dim target As String = "is"
      Dim anyOf As Char() = target.ToCharArray()
      
      start = str.Length - 1
      Console.WriteLine("The last character occurrence  from position {0} to 0.", start)
      Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)
      Console.Write("A character in '{0}' occurs at position: ", target)
      
      at = str.LastIndexOfAny(anyOf)
      If at > - 1 Then
         Console.Write(at)
      Else
         Console.Write("(not found)")
      End If
      Console.Write("{0}{0}{0}", Environment.NewLine)
   End Sub
End Class
'
'This example produces the following results:
'The last character occurrence  from position 66 to 0.
'0----+----1----+----2----+----3----+----4----+----5----+----6----+-
'0123456789012345678901234567890123456789012345678901234567890123456
'Now is the time for all good men to come to the aid of their party.
'
'A character in 'is' occurs at position: 58
'
'
'

Remarks

Index numbering starts from zero.

This method begins searching at the last character position of this instance and proceeds backward toward the beginning until either a character in anyOf is found or the first character position has been examined. The search is case-sensitive.

This method performs an ordinal (culture-insensitive) search, where a character is considered equivalent to another character only if their Unicode scalar values are the same. To perform a culture-sensitive search, use the CompareInfo.LastIndexOf method, where a Unicode scalar value representing a precomposed character, such as the ligature "Æ" (U+00C6), might be considered equivalent to any occurrence of the character's components in the correct sequence, such as "AE" (U+0041, U+0045), depending on the culture.

See also

• Char
• Int32
• Array
• IndexOf(Char)
• IndexOfAny(Char[])
• LastIndexOf(Char)

LastIndexOfAny(Char[], Int32)

Source:

String.Searching.cs

Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array. The search starts at a specified character position and proceeds backward toward the beginning of the string.

public:
 int LastIndexOfAny(cli::array <char> ^ anyOf, int startIndex);

public int LastIndexOfAny (char[] anyOf, int startIndex);

member this.LastIndexOfAny : char[] * int -> int

Public Function LastIndexOfAny (anyOf As Char(), startIndex As Integer) As Integer

Parameters

anyOf

Char[]

A Unicode character array containing one or more characters to seek.

startIndex

Int32

The search starting position. The search proceeds from startIndex toward the beginning of this instance.

Returns

Int32

The index position of the last occurrence in this instance where any character in anyOf was found; -1 if no character in anyOf was found or if the current instance equals Empty.

Exceptions

ArgumentNullException

anyOf is null.

ArgumentOutOfRangeException

The current instance does not equal Empty, and startIndex specifies a position that is not within this instance.

Examples

The following example finds the index of the last occurrence of any character in the string "is" within a substring of another string.

// Sample for String::LastIndexOfAny(Char, Int32)
using namespace System;
int main()
{
   String^ br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
   String^ br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
   String^ str = "Now is the time for all good men to come to the aid of their party.";
   int start;
   int at;
   String^ target = "is";
   array<Char>^anyOf = target->ToCharArray();
   start = (str->Length - 1) / 2;
   Console::WriteLine( "The last character occurrence  from position {0} to 0.", start );
   Console::WriteLine( "{1}{0}{2}{0}{3}{0}", Environment::NewLine, br1, br2, str );
   Console::Write( "A character in '{0}' occurs at position: ", target );
   at = str->LastIndexOfAny( anyOf, start );
   if ( at > -1 )
      Console::Write( at );
   else
      Console::Write( "(not found)" );

   Console::Write( "{0}{0}{0}", Environment::NewLine );
}

/*
This example produces the following results:
The last character occurrence  from position 33 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 12


*/

// Sample for String.LastIndexOfAny(Char[], Int32)
using System;

class Sample {
    public static void Main() {

    string br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
    string br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
    string str = "Now is the time for all good men to come to the aid of their party.";
    int start;
    int at;
    string target = "is";
    char[] anyOf = target.ToCharArray();

    start = (str.Length-1)/2;
    Console.WriteLine("The last character occurrence  from position {0} to 0.", start);
    Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str);
    Console.Write("A character in '{0}' occurs at position: ", target);

    at = str.LastIndexOfAny(anyOf, start);
    if (at > -1)
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.Write("{0}{0}{0}", Environment.NewLine);
    }
}
/*
This example produces the following results:
The last character occurrence  from position 33 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 12


*/

// Sample for String.LastIndexOfAny(Char[], Int32)
open System

let br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
let br2 = "0123456789012345678901234567890123456789012345678901234567890123456"
let str = "Now is the time for all good men to come to the aid of their party."
let target = "is"
let anyOf = target.ToCharArray()

let start = (str.Length - 1) / 2
printfn $"The last character occurrence  from position {start} to 0."
printfn $"{br1}{Environment.NewLine}{br2}{Environment.NewLine}{str}{Environment.NewLine}"
printf $"A character in '{target}' occurs at position: "

let at = str.LastIndexOfAny(anyOf, start)
if at > -1 then
    printf $"{at}"
else
    printf "(not found)"
printf $"{Environment.NewLine}{Environment.NewLine}{Environment.NewLine}"
(*
This example produces the following results:
The last character occurrence  from position 33 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'is' occurs at position: 12


*)

' Sample for String.LastIndexOfAny(Char[], Int32)
 _

Class Sample
   
   Public Shared Sub Main()
      
      Dim br1 As String = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
      Dim br2 As String = "0123456789012345678901234567890123456789012345678901234567890123456"
      Dim str As String = "Now is the time for all good men to come to the aid of their party."
      Dim start As Integer
      Dim at As Integer
      Dim target As String = "is"
      Dim anyOf As Char() = target.ToCharArray()
      
      start =(str.Length - 1) / 2
      Console.WriteLine("The last character occurrence  from position {0} to 0.", start)
      Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)
      Console.Write("A character in '{0}' occurs at position: ", target)
      
      at = str.LastIndexOfAny(anyOf, start)
      If at > - 1 Then
         Console.Write(at)
      Else
         Console.Write("(not found)")
      End If
      Console.Write("{0}{0}{0}", Environment.NewLine)
   End Sub
End Class
'
'This example produces the following results:
'The last character occurrence  from position 33 to 0.
'0----+----1----+----2----+----3----+----4----+----5----+----6----+-
'0123456789012345678901234567890123456789012345678901234567890123456
'Now is the time for all good men to come to the aid of their party.
'
'A character in 'is' occurs at position: 12
'
'
'

Remarks

Index numbering starts from zero.

This method begins searching at the startIndex character position of this instance and proceeds backward toward the beginning until either a character in anyOf is found or the first character position has been examined. The search is case-sensitive.

This method performs an ordinal (culture-insensitive) search, where a character is considered equivalent to another character only if their Unicode scalar values are the same. To perform a culture-sensitive search, use the CompareInfo.LastIndexOf method, where a Unicode scalar value representing a precomposed character, such as the ligature "Æ" (U+00C6), might be considered equivalent to any occurrence of the character's components in the correct sequence, such as "AE" (U+0041, U+0045), depending on the culture.

See also

• Char
• Int32
• Array
• IndexOf(Char)
• IndexOfAny(Char[])
• LastIndexOf(Char)

LastIndexOfAny(Char[], Int32, Int32)

Source:

String.Searching.cs

Reports the zero-based index position of the last occurrence in this instance of one or more characters specified in a Unicode array. The search starts at a specified character position and proceeds backward toward the beginning of the string for a specified number of character positions.

public:
 int LastIndexOfAny(cli::array <char> ^ anyOf, int startIndex, int count);

public int LastIndexOfAny (char[] anyOf, int startIndex, int count);

member this.LastIndexOfAny : char[] * int * int -> int

Public Function LastIndexOfAny (anyOf As Char(), startIndex As Integer, count As Integer) As Integer

Parameters

anyOf

Char[]

A Unicode character array containing one or more characters to seek.

startIndex

Int32

The search starting position. The search proceeds from startIndex toward the beginning of this instance.

count

Int32

The number of character positions to examine.

Returns

Int32

The index position of the last occurrence in this instance where any character in anyOf was found; -1 if no character in anyOf was found or if the current instance equals Empty.

Exceptions

ArgumentNullException

anyOf is null.

ArgumentOutOfRangeException

The current instance does not equal Empty, and count or startIndex is negative.

-or-

The current instance does not equal Empty, and startIndex minus count + 1 is less than zero.

Examples

The following example finds the index of the last occurrence of any character in the string "aid" within a substring of another string.

// Sample for String::LastIndexOfAny(Char[], Int32, Int32)
using namespace System;
int main()
{
   String^ br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
   String^ br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
   String^ str = "Now is the time for all good men to come to the aid of their party.";
   int start;
   int at;
   int count;
   String^ target = "aid";
   array<Char>^anyOf = target->ToCharArray();
   start = ((str->Length - 1) * 2) / 3;
   count = (str->Length - 1) / 3;
   Console::WriteLine( "The last character occurrence from position {0} for {1} characters.", start, count );
   Console::WriteLine( "{1}{0}{2}{0}{3}{0}", Environment::NewLine, br1, br2, str );
   Console::Write( "A character in '{0}' occurs at position: ", target );
   at = str->LastIndexOfAny( anyOf, start, count );
   if ( at > -1 )
      Console::Write( at );
   else
      Console::Write( "(not found)" );

   Console::Write( "{0}{0}{0}", Environment::NewLine );
}

/*
This example produces the following results:
The last character occurrence from position 44 for 22 characters.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'aid' occurs at position: 27
*/

// Sample for String.LastIndexOfAny(Char[], Int32, Int32)
using System;

class Sample {
    public static void Main() {

    string br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
    string br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
    string str = "Now is the time for all good men to come to the aid of their party.";
    int start;
    int at;
    int count;
    string target = "aid";
    char[] anyOf = target.ToCharArray();

    start = ((str.Length-1)*2)/3;
    count = (str.Length-1)/3;
    Console.WriteLine("The last character occurrence from position {0} for {1} characters.", start, count);
    Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str);
    Console.Write("A character in '{0}' occurs at position: ", target);

    at = str.LastIndexOfAny(anyOf, start, count);
    if (at > -1)
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.Write("{0}{0}{0}", Environment.NewLine);
    }
}
/*
This example produces the following results:
The last character occurrence from position 44 for 22 characters.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'aid' occurs at position: 27
*/

// Sample for String.LastIndexOfAny(Char[], Int32, Int32)
open System

let br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
let br2 = "0123456789012345678901234567890123456789012345678901234567890123456"
let str = "Now is the time for all good men to come to the aid of their party."
let target = "aid"
let anyOf = target.ToCharArray()

let start = ((str.Length - 1) * 2) / 3
let count = (str.Length - 1) / 3
printfn $"The last character occurrence from position {start} for {count} characters."
printfn $"{br1}{Environment.NewLine}{br2}{Environment.NewLine}{str}{Environment.NewLine}"
printf $"A character in '{target}' occurs at position: "

let at = str.LastIndexOfAny(anyOf, start, count)
if at > -1 then
    printf $"{at}"
else
    printf "(not found)"
printf $"{Environment.NewLine}{Environment.NewLine}{Environment.NewLine}"
(*
This example produces the following results:
The last character occurrence from position 44 for 22 characters.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'aid' occurs at position: 27
*)

' Sample for String.LastIndexOfAny(Char[], Int32, Int32)
 _

Class Sample
   
   Public Shared Sub Main()
      
      Dim br1 As String = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
      Dim br2 As String = "0123456789012345678901234567890123456789012345678901234567890123456"
      Dim str As String = "Now is the time for all good men to come to the aid of their party."
      Dim start As Integer
      Dim at As Integer
      Dim count As Integer
      Dim target As String = "aid"
      Dim anyOf As Char() = target.ToCharArray()
      
      start =(str.Length - 1) * 2 / 3
      count =(str.Length - 1) / 3
      Console.WriteLine("The last character occurrence from position {0} for {1} characters.", start, count)
      Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)
      Console.Write("A character in '{0}' occurs at position: ", target)
      
      at = str.LastIndexOfAny(anyOf, start, count)
      If at > - 1 Then
         Console.Write(at)
      Else
         Console.Write("(not found)")
      End If
      Console.Write("{0}{0}{0}", Environment.NewLine)
   End Sub
End Class
'
'This example produces the following results:
'The last character occurrence from position 44 for 22 characters.
'0----+----1----+----2----+----3----+----4----+----5----+----6----+-
'0123456789012345678901234567890123456789012345678901234567890123456
'Now is the time for all good men to come to the aid of their party.
'
'A character in 'aid' occurs at position: 27
'

Remarks

Index numbering starts from zero.

This method begins searching at the startIndex character position of this instance and proceeds backward toward the beginning until either a character in anyOf is found or count character positions have been examined. The search is case-sensitive.

This method performs an ordinal (culture-insensitive) search, where a character is considered equivalent to another character only if their Unicode scalar values are the same. To perform a culture-sensitive search, use the CompareInfo.LastIndexOf method, where a Unicode scalar value representing a precomposed character, such as the ligature "Æ" (U+00C6), might be considered equivalent to any occurrence of the character's components in the correct sequence, such as "AE" (U+0041, U+0045), depending on the culture.

See also

• Char
• Int32
• Array
• IndexOf(Char)
• IndexOfAny(Char[])
• LastIndexOf(Char)