ReadOnlySpanExtensionLastIndexOf Method

Specifies the zero based index position of the last occurrence of a specified character sequence in span. The search begins at a specified character position and runs backwards to the beginning of the character span for a specified number of character positions. A parameter specifies the type of comparison to be performed when searching for the specified character sequence.

Definition

Namespace: FolkerKinzel.Strings
Assembly: FolkerKinzel.Strings (in FolkerKinzel.Strings.dll) Version: 9.4.0+10a7d4d71aa960998e32ac0ac6c4fcbe4164c917

C#

public static int LastIndexOf(
	this ReadOnlySpan<char> span,
	ReadOnlySpan<char> value,
	int startIndex,
	int count,
	StringComparison comparisonType
)

VB

<ExtensionAttribute>
Public Shared Function LastIndexOf ( 
	span As ReadOnlySpan(Of Char),
	value As ReadOnlySpan(Of Char),
	startIndex As Integer,
	count As Integer,
	comparisonType As StringComparison
) As Integer

C++

public:
[ExtensionAttribute]
static int LastIndexOf(
	ReadOnlySpan<wchar_t> span, 
	ReadOnlySpan<wchar_t> value, 
	int startIndex, 
	int count, 
	StringComparison comparisonType
)

F#

[<ExtensionAttribute>]
static member LastIndexOf : 
        span : ReadOnlySpan<char> * 
        value : ReadOnlySpan<char> * 
        startIndex : int * 
        count : int * 
        comparisonType : StringComparison -> int

Parameters

span ReadOnlySpanChar: The span to search.
value ReadOnlySpanChar: The character span to search for.
startIndex Int32: The start index of the search. The search is done backwards to the beginning of span.
count Int32: The number of character positions to examine.
comparisonType StringComparison: One of the enumeration values that specifies the rules for the comparison.

Return Value

Int32
The zero-based start index of the value parameter if this character sequence was found, or -1 if it was not found or span is empty.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type ReadOnlySpanChar. 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).

Exceptions

ArgumentOutOfRangeException

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

- or -

span is not Empty and count is negative or startIndex - count + 1 is less than zero.

ArgumentException

comparisonType is not a defined value of the StringComparison enum.