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String.LastIndexOf Method (String, Int32, Int32)

Reports the zero-based index position of the last occurrence of a specified string within this instance. The search starts at a specified character position and examines a specified number of character positions.

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

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

Parameters

value
Type: System.String
The string to seek.
startIndex
Type: System.Int32
The search starting position. 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 string is found, or -1 if it is not found or if the current instance equals String.Empty. If value is Empty, the return value is the smaller of startIndex and the last index position in this instance.

ExceptionCondition
ArgumentNullException

value is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

count is negative.

-or-

The current instance does not equal String.Empty, and startIndex is negative.

-or-

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

-or-

The current instance does not equal String.Empty and startIndex - count + 1 specifies a position that is not within this instance.

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

The search begins at the startIndex character position of this instance and proceeds backward toward the beginning 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.

This method performs a word (case-sensitive and culture-sensitive) search using the current culture.

Notes to Callers

As explained in Best Practices for Using Strings in the .NET Framework, we recommend that you avoid calling string comparison methods that substitute default values and instead call methods that require parameters to be explicitly specified. To perform this operation by using the comparison rules of the current culture, call the LastIndexOf(String, Int32, Int32, StringComparison) method overload with a value of StringComparison.CurrentCulture for its comparisonType parameter.

The following example finds the index of all occurrences of a string in 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.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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