String.IndexOfAny Method (Char[])


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

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public int IndexOfAny(
	char[] anyOf


Type: System.Char[]

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

Return Value

Type: System.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.

Exception Condition

anyOf is null.

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.

The following example finds the first vowel in a string.

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

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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