String::LastIndexOf Method (String, 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.
Assembly: mscorlib (in mscorlib.dll)
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.
Return Value
Type: System::Int32The 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 String::Empty, the return value is the smaller of startIndex and the last index position in this instance.
| Exception | Condition |
|---|---|
| ArgumentNullException | value is nullptr. |
| ArgumentOutOfRangeException | The current instance does not equal String::Empty, and startIndex is less than zero or greater than the length of the current instance. -or- The current instance equals Empty and startIndex is greater 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.
The search begins at the startIndex character position of this instance and proceeds backward toward the beginning until either value is found or the first character position has been examined. For example, if startIndex is Length - 1, the method searches every character from the last character in the string to the beginning.
This method performs a word (case-sensitive and culture-sensitive) search using the current culture.
Notes to CallersAs 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 find the index of a substring that precedes a particular character position by using the comparison rules of the current culture, call the LastIndexOf(String, 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 target string, working from the end of the target string to the start of the target string.
// Sample for String::LastIndexOf(String, Int32) using namespace System; int main() { String^ br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"; String^ br2 = "0123456789012345678901234567890123456789012345678901234567890123456"; String^ str = "Now is the time for all good men to come to the aid of their party."; int start; int at; start = str->Length - 1; Console::WriteLine( "All occurrences of 'he' from position {0} to 0.", start ); Console::WriteLine( "{0}\n{1}\n{2}\n", br1, br2, str ); Console::Write( "The string 'he' occurs at position(s): " ); at = 0; while ( (start > -1) && (at > -1) ) { at = str->LastIndexOf( "he", start ); if ( at > -1 ) { Console::Write( " {0} ", at ); start = at - 1; } } Console::WriteLine(); } /* This example produces the following results: All occurrences of 'he' from position 66 to 0. 0----+----1----+----2----+----3----+----4----+----5----+----6----+- 0123456789012345678901234567890123456789012345678901234567890123456 Now is the time for all good men to come to the aid of their party. The string 'he' occurs at position(s): 56 45 8 */
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.