Reports the zero-based index of the first occurrence in this instance of any character in a specified array of Unicode characters.
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.
Type Reason ArgumentNullException anyOf is a null reference.
Index numbering starts from zero.
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 System.Globalization.CompareInfo.IndexOf(string, char) 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.