Collection < T > .Add(T)方法用于将一个对象添加到Collection < T >的末尾。
句法 :
public void Add (T item);
这里, item是要添加到Collection < T >末尾的对象。对于引用类型,该值可以为null。
下面给出了一些示例,以更好地理解实现:
范例1:
// C# code to add an object to
// the end of the Collection
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
class GFG {
// Driver code
public static void Main()
{
// Creating a collection of strings
Collection myColl = new Collection();
myColl.Add("A");
myColl.Add("B");
myColl.Add("C");
myColl.Add("D");
myColl.Add("E");
// Displaying the number of elements in Collection
Console.WriteLine("The number of elements in myColl are : "
+ myColl.Count);
// Displaying the elements in Collection
Console.WriteLine("The elements in myColl are : ");
foreach(string str in myColl)
{
Console.WriteLine(str);
}
}
}
输出:
The number of elements in myColl are : 5
The elements in myColl are :
A
B
C
D
E
范例2:
// C# code to add an object to
// the end of the Collection
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
class GFG {
// Driver code
public static void Main()
{
// Creating a collection of ints
Collection myColl = new Collection();
myColl.Add(2);
myColl.Add(3);
myColl.Add(4);
myColl.Add(5);
// Displaying the number of elements in Collection
Console.WriteLine("The number of elements in myColl are : "
+ myColl.Count);
// Displaying the elements in Collection
Console.WriteLine("The elements in myColl are : ");
foreach(int i in myColl)
{
Console.WriteLine(i);
}
}
}
输出:
The number of elements in myColl are : 4
The elements in myColl are :
2
3
4
5
笔记:
- Collection < T >接受null作为引用类型的有效值,并允许重复的元素。
- 此方法是O(1)操作。
参考:
- https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.objectmodel.collection-1.add?view=netframework-4.7.2