String.LastIndexOf Method (Char, Int32, Int32)

 

Reports the zero-based index position of the last occurrence of the specified Unicode character in a substring within this instance. The search starts at a specified character position and proceeds backward toward the beginning of the string for a specified number of character positions.

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

member LastIndexOf : 
        value:char *
        startIndex:int *
        count:int -> int

Parameters

value
Type: System.Char

The Unicode character to seek.

startIndex
Type: System.Int32

The starting position of the search. The search proceeds from startIndex toward the beginning of this instance.

count
Type: System.Int32

The number of character positions to examine.

Return Value

Type: System.Int32

The zero-based index position of value if that character is found, or -1 if it is not found or if the current instance equals String.Empty.

Exception Condition
ArgumentOutOfRangeException

The current instance does not equal String.Empty, and startIndex is less than zero or greater than or equal to the length of this instance.

-or-

The current instance does not equal String.Empty, and startIndex - count + 1 is less than zero.

Index numbering starts from zero. That is, the first character in the string is at index zero and the last is at Length - 1.

This method begins searching at the startIndex character position and proceeds backward toward the beginning of this instance until either value is found or count character positions have been examined. For example, if startIndex is Length - 1, the method searches backward count characters from the last character in the string. The search 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.LastIndexOf 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 index of all occurrences of a character in a substring, working from the end of the substring to the start of the substring.

No code example is currently available or this language may not be supported.

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