📜  C#|从列表中删除指定的元素

📅  最后修改于: 2021-05-29 19:40:15             🧑  作者: Mango

List.Remove(T)方法用于从列表中删除第一次出现的特定对象。

列表的属性:

  • 它与数组不同。列表可以动态调整大小,但数组则不能。
  • List类可以接受null作为引用类型的有效值,并且还允许重复元素
  • 如果计数等于容量,则列表的容量将通过重新分配内部数组而自动增加。在添加新元素之前,现有元素将被复制到新数组。

句法:

public bool Remove (T item);

范围:

返回类型:如果已成功删除,则此方法返回True。否则返回False

注意:如果在列表中未找到项目,则此方法返回False。

以下程序说明了如何从列表中删除指定的元素:

范例1:

// C# program to remove the specified
// element from the List
using System;
using System.Collections.Generic;
  
class Geeks {
  
    // Main Method
    public static void Main(String[] args)
    {
  
        // Creating a List of integers
        List firstlist = new List();
  
        // adding elements in firstlist
        firstlist.Add(1);
        firstlist.Add(2);
        firstlist.Add(3);
        firstlist.Add(4);
  
        // Displaying elements of firstlist
        // by using foreach loop
        Console.WriteLine("Before Removing");
        foreach(int element in firstlist)
        {
            Console.WriteLine(element);
        }
  
        // Removing 2 from the firstlist & Displaying
        // the remaining firstlist elements
        Console.WriteLine("After Removing");
        firstlist.Remove(2);
        foreach(int element in firstlist)
        {
            Console.WriteLine(element);
        }
    }
}

输出:

Before Removing
1
2
3
4
After Removing
1
3
4

范例2:

// C# program to remove the specified
// element from the List
using System;
using System.Collections.Generic;
  
class Geeks {
  
    // Main Method
    public static void Main(String[] args)
    {
  
        // Creating a List of integers
        List firstlist = new List();
  
        // adding elements in firstlist
        firstlist.Add(1);
        firstlist.Add(2);
        firstlist.Add(3);
        firstlist.Add(4);
  
        // Adding some duplicate
        // elements in firstlist
        firstlist.Add(2);
        firstlist.Add(4);
  
        // Displaying elements of firstlist
        // by using foreach loop
        Console.WriteLine("Before Removing");
        foreach(int element in firstlist)
        {
            Console.WriteLine(element);
        }
  
        // Removing first occurrence of 2
        // from the firstlist & Displaying
        // the remaining firstlist elements
        Console.WriteLine("After Removing");
        firstlist.Remove(2);
        foreach(int element in firstlist)
        {
            Console.WriteLine(element);
        }
    }
}

输出:

Before Removing
1
2
3
4
2
4
After Removing
1
3
4
2
4

参考:

  • https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.generic.list-1.remove?view=netframework-4.7.2