Gets or sets the total number of elements the internal data structure can hold without resizing.
Assembly: mscorlib (in mscorlib.dll)
If the capacity is significantly larger than the count and you want to reduce the memory used by the List<'T>, you can decrease capacity by calling the TrimExcess method or by setting the property explicitly to a lower value. When the value of is set explicitly, the internal array is also reallocated to accommodate the specified capacity, and all the elements are copied.
Retrieving the value of this property is an O(1) operation; setting the property is an O(n) operation, where n is the new capacity.
The following example shows the Add method has been used to add several items, the items are listed, and then the property is displayed again, along with the Count property, to show that the capacity has been increased as needed.property at several points in the life of a list. The default constructor is used to create a list of strings with a capacity of 0, and the property is displayed to demonstrate this. After the
[<EntryPoint>] let main argv = // We refer to System.Collections.Generic.List<'T> by its type // abbreviation ResizeArray<'T> to avoid conflict with the List module. // Note: In F# code, F# linked lists are usually preferred over // ResizeArray<'T> when an extendable collection is required. let dinosaurs = ResizeArray<_>() // Write out the dinosaurs in the ResizeArray. let printDinosaurs() = printfn "" dinosaurs |> Seq.iter (fun p -> printfn "%O" p) printfn "\nCapacity: %i" dinosaurs.Capacity dinosaurs.Add("Tyrannosaurus") dinosaurs.Add("Amargasaurus") dinosaurs.Add("Mamenchisaurus") dinosaurs.Add("Deinonychus") dinosaurs.Add("Compsognathus") printDinosaurs() printfn "\nCapacity: %i" dinosaurs.Capacity printfn "Count: %i" dinosaurs.Count printfn "\nContains(\"Deinonychus\"): %b" (dinosaurs.Contains("Deinonychus")) printfn "\nInsert(2, \"Compsognathus\")" dinosaurs.Insert(2, "Compsognathus") printDinosaurs() // Shows accessing the list using the Item property. printfn "\ndinosaurs: %s" dinosaurs. printfn "\nRemove(\"Compsognathus\")" dinosaurs.Remove("Compsognathus") |> ignore printDinosaurs() dinosaurs.TrimExcess() printfn "\nTrimExcess()" printfn "Capacity: %i" dinosaurs.Capacity printfn "Count: %i" dinosaurs.Count dinosaurs.Clear() printfn "\nClear()" printfn "Capacity: %i" dinosaurs.Capacity printfn "Count: %i" dinosaurs.Count 0 // return an integer exit code (* This code example produces the following output: Capacity: 0 Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus Capacity: 8 Count: 5 Contains("Deinonychus"): true Insert(2, "Compsognathus") Tyrannosaurus Amargasaurus Compsognathus Mamenchisaurus Deinonychus Compsognathus dinosaurs: Mamenchisaurus Remove("Compsognathus") Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus TrimExcess() Capacity: 5 Count: 5 Clear() Capacity: 5 Count: 0 *)
Available since 8
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Available since 8.1