Array::LastIndexOf<T> Method (array<T>, T, Int32)
Searches for the specified object and returns the index of the last occurrence within the range of elements in the Array that extends from the first element to the specified index.
Assembly: mscorlib (in mscorlib.dll)
public: generic<typename T> static int LastIndexOf( array<T>^ array, T value, int startIndex )
Type Parameters
- T
The type of the elements of the array.
Parameters
- array
- Type: array<T>
The one-dimensional, zero-based Array to search.
- value
- Type: T
The object to locate in array.
- startIndex
- Type: System::Int32
The zero-based starting index of the backward search.
Return Value
Type: System::Int32The zero-based index of the last occurrence of value within the range of elements in array that extends from the first element to startIndex, if found; otherwise, –1.
| Exception | Condition |
|---|---|
| ArgumentNullException | array is nullptr. |
| ArgumentOutOfRangeException | startIndex is outside the range of valid indexes for array. |
The Array is searched backward starting at startIndex and ending at the first element.
The elements are compared to the specified value using the Object::Equals method. If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.
This method is an O(n) operation, where n is the number of elements from the beginning of array to startIndex.
The following code example demonstrates all three generic overloads of the LastIndexOf method. An array of strings is created, with one entry that appears twice, at index location 0 and index location 5. The LastIndexOf<T>(array<T>, T) method overload searches the entire array from the end, and finds the second occurrence of the string. The LastIndexOf<T>(array<T>, T, Int32) method overload is used to search the array backward beginning with index location 3 and continuing to the beginning of the array, and finds the first occurrence of the string. Finally, the LastIndexOf<T>(array<T>, T, Int32, Int32) method overload is used to search a range of four entries, beginning at index location 4 and extending backward (that is, it searches the items at locations 4, 3, 2, and 1); this search returns –1 because there are no instances of the search string in that range.
using namespace System; void main() { array<String^>^ dinosaurs = { "Tyrannosaurus", "Amargasaurus", "Mamenchisaurus", "Brachiosaurus", "Deinonychus", "Tyrannosaurus", "Compsognathus" }; Console::WriteLine(); for each(String^ dinosaur in dinosaurs ) { Console::WriteLine(dinosaur); } Console::WriteLine( "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", Array::LastIndexOf(dinosaurs, "Tyrannosaurus")); Console::WriteLine( "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}", Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 3)); Console::WriteLine( "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}", Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4)); } /* This code example produces the following output: Tyrannosaurus Amargasaurus Mamenchisaurus Brachiosaurus Deinonychus Tyrannosaurus Compsognathus Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5 Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0 Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1 */
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.