String.IndexOfAny Method

Definition

Namespace:

System

Assemblies:

netstandard.dll, System.Runtime.dll

Reports the index of the first occurrence in this instance of any character in a specified array of Unicode characters. The method returns -1 if the characters in the array are not found in this instance.

Overloads

IndexOfAny(Char[])	Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters.
IndexOfAny(Char[], Int32)	Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters. The search starts at a specified character position.
IndexOfAny(Char[], Int32, Int32)	Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters. The search starts at a specified character position and examines a specified number of character positions.

IndexOfAny(Char[])

Source:

String.Searching.cs

Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters.

C#

public int IndexOfAny(char[] anyOf);

Parameters

anyOf

Char[]

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

Returns

Int32

The zero-based index position of the first 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 first vowel in a string.

C#

using System;

public class Example
{
   public static void Main()
   {
      char[] chars = { 'a', 'e', 'i', 'o', 'u', 'y', 
                       'A', 'E', 'I', 'O', 'U', 'Y' };
      String s = "The long and winding road...";
      Console.WriteLine("The first vowel in \n   {0}\nis found at position {1}", 
                        s, s.IndexOfAny(chars) + 1);                         
   }
}
// The example displays the following output:
//       The first vowel in
//          The long and winding road...
//       is found at position 3

Remarks

Index numbering starts from zero.

The search for anyOf is case-sensitive. If anyOf is an empty array, the method finds a match at the beginning of the string (that is, at index zero).

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.IndexOf 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

• IndexOf(Char)
• LastIndexOf(Char)
• LastIndexOfAny(Char[])

IndexOfAny(Char[], Int32)

Source:

String.Searching.cs

Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters. The search starts at a specified character position.

C#

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

Parameters

anyOf

Char[]

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

startIndex

Int32

The search starting position.

Returns

Int32

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

Exceptions

ArgumentNullException

anyOf is null.

ArgumentOutOfRangeException

startIndex is negative.

-or-

startIndex is greater than the number of characters in this instance.

Examples

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

C#

// Sample for String.IndexOfAny(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/2;
    Console.WriteLine();
    Console.WriteLine("The first character occurrence from position {0} to {1}.",
                           start, str.Length-1);
    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.IndexOfAny(anyOf, start);
    if (at > -1)
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.WriteLine();
    }
}
/*

The first character occurrence from position 33 to 66.
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: 49

*/

Remarks

Index numbering starts from zero. The startIndex parameter can range from 0 to one less than the length of the string instance.

The search ranges from startIndex to the end of the string.

The search for anyOf 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 value are the same. To perform a culture-sensitive search, use the CompareInfo.IndexOf 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)
• LastIndexOf(Char)
• LastIndexOfAny(Char[])

IndexOfAny(Char[], Int32, Int32)

Source:

String.Searching.cs

Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters. The search starts at a specified character position and examines a specified number of character positions.

C#

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

Parameters

anyOf

Char[]

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

startIndex

Int32

The search starting position.

count

Int32

The number of character positions to examine.

Returns

Int32

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

Exceptions

ArgumentNullException

anyOf is null.

ArgumentOutOfRangeException

count or startIndex is negative.

-or-

count + startIndex is greater than the number of characters in this instance.

Examples

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

C#

// Sample for String.IndexOfAny(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)/3;
    count = (str.Length-1)/4;
    Console.WriteLine();
    Console.WriteLine("The first 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.IndexOfAny(anyOf, start, count);
    if (at > -1)
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.WriteLine();
    }
}
/*

The first character occurrence from position 22 for 16 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

The search begins at startIndex and continues to startIndex + count -1. The character at startIndex + count is not included in the search.

Index numbering starts from zero. The startIndex parameter can range from 0 to one less than the length of the string instance.

The search for anyOf 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 value are the same. To perform a culture-sensitive search, use the CompareInfo.IndexOf 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)
• LastIndexOf(Char)
• LastIndexOfAny(Char[])