Collection<T>.Add(T) メソッド

定義

Collection<T> の末尾にオブジェクトを追加します。Adds an object to the end of the Collection<T>.

public:
 virtual void Add(T item);
public void Add (T item);
abstract member Add : 'T -> unit
override this.Add : 'T -> unit
Public Sub Add (item As T)

パラメーター

item
T

Collection<T> の末尾に追加するオブジェクト。The object to be added to the end of the Collection<T>. 参照型の場合は null の値を使用できます。The value can be null for reference types.

実装

次のコード例は、のCollection<T>プロパティとメソッドの多くを示しています。The following code example demonstrates many of the properties and methods of Collection<T>. このコード例では、文字列のコレクションを作成Addし、メソッドを使用して複数Countの文字列を追加し、を表示して、文字列を一覧表示します。The code example creates a collection of strings, uses the Add method to add several strings, displays the Count, and lists the strings. この例ではIndexOf 、メソッドを使用して文字列のインデックスをContains検索し、メソッドを使用して文字列がコレクション内に存在するかどうかを確認します。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. この例では、 Insertメソッドを使用して文字列を挿入し、既定Item[Int32]のプロパティ (のC#インデクサー) を使用して文字列を取得して設定します。The example inserts a string using the Insert method and retrieves and sets strings using the default Item[Int32] property (the indexer in C#). この例では、メソッドとインデックスRemove RemoveAtを使用して、メソッドを使用して文字列 id によって文字列を削除します。The example removes strings by string identity using the Remove method and by index using the RemoveAt method. 最後に、 Clearメソッドを使用して、コレクションからすべての文字列をクリアします。Finally, the Clear method is used to clear all strings from the collection.

using namespace System;
using namespace System::Collections::Generic;
using namespace System::Collections::ObjectModel;

public ref class Demo
{
public:
    static void Main()
    {
        Collection<String^>^ dinosaurs = gcnew Collection<String^>();

        dinosaurs->Add("Psitticosaurus");
        dinosaurs->Add("Caudipteryx");
        dinosaurs->Add("Compsognathus");
        dinosaurs->Add("Muttaburrasaurus");

        Console::WriteLine("{0} dinosaurs:", dinosaurs->Count);
        Display(dinosaurs);

        Console::WriteLine("\nIndexOf(\"Muttaburrasaurus\"): {0}",
            dinosaurs->IndexOf("Muttaburrasaurus"));

        Console::WriteLine("\nContains(\"Caudipteryx\"): {0}",
            dinosaurs->Contains("Caudipteryx"));

        Console::WriteLine("\nInsert(2, \"Nanotyrannus\")");
        dinosaurs->Insert(2, "Nanotyrannus");
        Display(dinosaurs);

        Console::WriteLine("\ndinosaurs[2]: {0}", dinosaurs[2]);

        Console::WriteLine("\ndinosaurs[2] = \"Microraptor\"");
        dinosaurs[2] = "Microraptor";
        Display(dinosaurs);

        Console::WriteLine("\nRemove(\"Microraptor\")");
        dinosaurs->Remove("Microraptor");
        Display(dinosaurs);

        Console::WriteLine("\nRemoveAt(0)");
        dinosaurs->RemoveAt(0);
        Display(dinosaurs);

        Console::WriteLine("\ndinosaurs.Clear()");
        dinosaurs->Clear();
        Console::WriteLine("Count: {0}", dinosaurs->Count);
    }

private:
    static void Display(Collection<String^>^ cs)
    {
        Console::WriteLine();
        for each( String^ item in cs )
        {
            Console::WriteLine(item);
        }
    }
};

int main()
{
    Demo::Main();
}

/* 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
 */
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;

public class Demo
{
    public static void Main()
    {
        Collection<string> dinosaurs = new Collection<string>();

        dinosaurs.Add("Psitticosaurus");
        dinosaurs.Add("Caudipteryx");
        dinosaurs.Add("Compsognathus");
        dinosaurs.Add("Muttaburrasaurus");

        Console.WriteLine("{0} dinosaurs:", dinosaurs.Count);
        Display(dinosaurs);
    
        Console.WriteLine("\nIndexOf(\"Muttaburrasaurus\"): {0}", 
            dinosaurs.IndexOf("Muttaburrasaurus"));

        Console.WriteLine("\nContains(\"Caudipteryx\"): {0}", 
            dinosaurs.Contains("Caudipteryx"));

        Console.WriteLine("\nInsert(2, \"Nanotyrannus\")");
        dinosaurs.Insert(2, "Nanotyrannus");
        Display(dinosaurs);

        Console.WriteLine("\ndinosaurs[2]: {0}", dinosaurs[2]);

        Console.WriteLine("\ndinosaurs[2] = \"Microraptor\"");
        dinosaurs[2] = "Microraptor";
        Display(dinosaurs);

        Console.WriteLine("\nRemove(\"Microraptor\")");
        dinosaurs.Remove("Microraptor");
        Display(dinosaurs);

        Console.WriteLine("\nRemoveAt(0)");
        dinosaurs.RemoveAt(0);
        Display(dinosaurs);

        Console.WriteLine("\ndinosaurs.Clear()");
        dinosaurs.Clear();
        Console.WriteLine("Count: {0}", dinosaurs.Count);
    }
    
    private static void Display(Collection<string> cs)
    {
        Console.WriteLine();
        foreach( string item in cs )
        {
            Console.WriteLine(item);
        }
    }
}

/* 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
 */
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

注釈

Collection<T>null 、参照型の有効な値としてを受け入れ、重複する要素を許可します。Collection<T> accepts null as a valid value for reference types and allows duplicate elements.

このメソッドは、O(1) 操作です。This method is an O(1) operation.

適用対象

こちらもご覧ください