StringExtensionLastIndexOfAny(String, ReadOnlySpan`1Char, Int32, Int32) Method

Returns the zero-based index position of the last occurrence of one of the specified characters in s. The search begins at a specified index and runs backwards to the beginning of the String for a specified number of character positions.

Definition

Namespace: FolkerKinzel.Strings
Assembly: FolkerKinzel.Strings (in FolkerKinzel.Strings.dll) Version: 9.4.0+10a7d4d71aa960998e32ac0ac6c4fcbe4164c917
C#
public static int LastIndexOfAny(
	this string s,
	ReadOnlySpan<char> anyOf,
	int startIndex,
	int count
)

Parameters

s  String
The String to search.
anyOf  ReadOnlySpanChar
A read-only character span that contains the characters to search for.
startIndex  Int32
The start index of the search. The search is done backwards to the beginning of s.
count  Int32
The number of character positions to examine.

Return Value

Int32
The zero-based index of the last occurrence of one of the specified Unicode characters in the specified part of s or -1 if none of these characters have been found in this area.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type String. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

MemoryExtensions.LastIndexOfAny<T>(ReadOnlySpan<T>, ReadOnlySpan<T>) is used for the comparison.

Exceptions

ArgumentNullExceptions is null.
ArgumentOutOfRangeException

s is not Empty and startIndex is less than zero or greater than or equal to the length of s

- or -

s is not Empty and startIndex - count + 1 is less than zero.

See Also