Collection.Remove Method
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Function Remove ( _ item As T _ ) As Boolean 'Usage Dim instance As Collection(Of T) Dim item As T Dim returnValue As Boolean returnValue = instance.Remove(item)
public final boolean Remove ( T item )
public final function Remove ( item : T ) : boolean
Not applicable.
Parameters
- item
The object to remove from the Collection. The value can be a null reference (Nothing in Visual Basic) for reference types.
Return Value
true if item is successfully removed; otherwise, false. This method also returns false if item was not found in the original Collection.This method determines equality using the default equality comparer EqualityComparer.Default for T, the type of values in the list.
This method performs a linear search; therefore, the average execution time is proportional to Count. That is, this method is an O(n) operation, where n is Count.
Notes to Inheritors: Derived classes can override RemoveItem to change the behavior of this method.The following code example demonstrates many of the properties and methods of Collection. The code example creates a collection of strings, uses the Add method to add several strings, displays the Count, and lists the strings. The example uses the IndexOf method to find the index of a string and the Contains method to determine whether a string is in the collection. The example inserts a string using the Insert method and retrieves and sets strings using the default Item property (the indexer in C#). The example removes strings by string identity using the Remove method and by index using the RemoveAt method. Finally, the Clear method is used to clear all strings from the collection.
Imports System Imports System.Collections.Generic Imports System.Collections.ObjectModel Public Class Demo Public Shared Sub Main() Dim dinosaurs As New Collection(Of String) dinosaurs.Add("Psitticosaurus") dinosaurs.Add("Caudipteryx") dinosaurs.Add("Compsognathus") dinosaurs.Add("Muttaburrasaurus") Console.WriteLine("{0} dinosaurs:", dinosaurs.Count) Display(dinosaurs) Console.WriteLine(vbLf & "IndexOf(""Muttaburrasaurus""): {0}", _ dinosaurs.IndexOf("Muttaburrasaurus")) Console.WriteLine(vbLf & "Contains(""Caudipteryx""): {0}", _ dinosaurs.Contains("Caudipteryx")) Console.WriteLine(vbLf & "Insert(2, ""Nanotyrannus"")") dinosaurs.Insert(2, "Nanotyrannus") Display(dinosaurs) Console.WriteLine(vbLf & "dinosaurs(2): {0}", dinosaurs(2)) Console.WriteLine(vbLf & "dinosaurs(2) = ""Microraptor""") dinosaurs(2) = "Microraptor" Display(dinosaurs) Console.WriteLine(vbLf & "Remove(""Microraptor"")") dinosaurs.Remove("Microraptor") Display(dinosaurs) Console.WriteLine(vbLf & "RemoveAt(0)") dinosaurs.RemoveAt(0) Display(dinosaurs) Console.WriteLine(vbLf & "dinosaurs.Clear()") dinosaurs.Clear() Console.WriteLine("Count: {0}", dinosaurs.Count) End Sub Private Shared Sub Display(ByVal cs As Collection(Of String)) Console.WriteLine() For Each item As String In cs Console.WriteLine(item) Next item End Sub End Class ' This code example produces the following output: ' '4 dinosaurs: ' 'Psitticosaurus 'Caudipteryx 'Compsognathus 'Muttaburrasaurus ' 'IndexOf("Muttaburrasaurus"): 3 ' 'Contains("Caudipteryx"): True ' 'Insert(2, "Nanotyrannus") ' 'Psitticosaurus 'Caudipteryx 'Nanotyrannus 'Compsognathus 'Muttaburrasaurus ' 'dinosaurs(2): Nanotyrannus ' 'dinosaurs(2) = "Microraptor" ' 'Psitticosaurus 'Caudipteryx 'Microraptor 'Compsognathus 'Muttaburrasaurus ' 'Remove("Microraptor") ' 'Psitticosaurus 'Caudipteryx 'Compsognathus 'Muttaburrasaurus ' 'RemoveAt(0) ' 'Caudipteryx 'Compsognathus 'Muttaburrasaurus ' 'dinosaurs.Clear() 'Count: 0
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.