C# C# |从哈希集中删除指定的元素

C# |从哈希集中删除指定的元素

原文:https://www . geesforgeks . org/c-sharp-从 a-hashset 中移除指定元素/

一个 HashSet 是一个独特元素的无序集合。它属于T3 系统。集合.通用命名空间。它用于我们希望防止在集合中插入重复项的情况。就性能而言，与列表相比更好。 HashSet < T >。移除(T)方法用于从 HashSet < T >对象中移除指定元素。

语法:

public bool Remove (T item);

这里，项是要删除的元素。

返回值:如果成功找到并移除元素，则该方法返回真，如果在 HashSet < T >对象中未找到项目，则返回假。

下面的例子说明了 HashSet 的使用。解除(T)法:

例 1:

// C# code to remove the specified 
// element from a HashSet
using System;
using System.Collections.Generic;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a HashSet of integers
        HashSet<int> mySet = new HashSet<int>();

        // Inserting even numbers less than
        // equal to 20 in HashSet mySet
        for (int i = 0; i < 10; i++) {
            mySet.Add(i * 2);
        }

        Console.WriteLine("The elements in HashSet are : ");

        // Displaying the elements in HashSet
        foreach(int i in mySet)
        {
            Console.WriteLine(i);
        }

        // Displaying the number of elements in HashSet
        Console.WriteLine("Number of elements are : " + mySet.Count);

        // Removing the element 10 if present
        if (mySet.Contains(10)) {
            mySet.Remove(10);
        }

        Console.WriteLine("The elements in HashSet are : ");

        // Displaying the elements in HashSet
        foreach(int i in mySet)
        {
            Console.WriteLine(i);
        }

        // Displaying the number of elements in HashSet
        Console.WriteLine("Number of elements are : " + mySet.Count);
    }
}

Output:

The elements in HashSet are : 
0
2
4
6
8
10
12
14
16
18
Number of elements are : 10
The elements in HashSet are : 
0
2
4
6
8
12
14
16
18
Number of elements are : 9

例 2:

// C# code to remove the specified
//  element from a HashSet
using System;
using System.Collections.Generic;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a HashSet of strings
        HashSet<string> mySet = new HashSet<string>();

        // Inserting elements into HashSet
        mySet.Add("Data Structures");
        mySet.Add("Algorithms");
        mySet.Add("Java");
        mySet.Add("Puzzles");
        mySet.Add("Coding");

        Console.WriteLine("The elements in HashSet are : ");

        // Displaying the elements in HashSet
        foreach(string i in mySet)
        {
            Console.WriteLine(i);
        }

        // Displaying the number of elements in HashSet
        Console.WriteLine("Number of elements are : " + mySet.Count);

        // Removing the element "JavaScript" if present
        if (mySet.Contains("JavaScript")) {
            mySet.Remove("JavaScript");
        }

        Console.WriteLine("The elements in HashSet are : ");

        // Displaying the elements in HashSet
        foreach(string i in mySet)
        {
            Console.WriteLine(i);
        }

        // Displaying the number of elements in HashSet
        Console.WriteLine("Number of elements are : " + mySet.Count);
    }
}

Output:

The elements in HashSet are : 
Data Structures
Algorithms
Java
Puzzles
Coding
Number of elements are : 5
The elements in HashSet are : 
Data Structures
Algorithms
Java
Puzzles
Coding
Number of elements are : 5

参考: