Collection<T>.Add(T) Metode
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Menambahkan objek ke akhir 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)
Parameter
- item
- T
Objek yang akan ditambahkan ke akhir Collection<T>. Nilainya bisa null
untuk jenis referensi.
Penerapan
Contoh
Contoh kode berikut menunjukkan banyak properti dan metode Collection<T>. Contoh kode membuat kumpulan string, menggunakan Add metode untuk menambahkan beberapa string, menampilkan Count, dan mencantumkan string. Contohnya menggunakan IndexOf metode untuk menemukan indeks string dan Contains metode untuk menentukan apakah string berada dalam koleksi. Contoh menyisipkan string menggunakan Insert metode dan mengambil dan mengatur string menggunakan properti default Item[] (pengindeks di C#). Contoh menghapus string berdasarkan identitas string menggunakan Remove metode dan dengan indeks menggunakan RemoveAt metode . Terakhir, Clear metode ini digunakan untuk menghapus semua string dari koleksi.
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
Keterangan
Collection<T>null
menerima sebagai nilai yang valid untuk jenis referensi dan memungkinkan elemen duplikat.
Metode ini adalah operasi O(1).