Dequeue()方法用于返回队列开始处的对象。此方法类似于Peek()方法。 Dequeue和Peek方法之间的唯一区别是Peek()方法不会修改Queue,但会修改Dequeue。此方法是O(1)运算,属于System.Collections
命名空间。
用法:
public virtual object Dequeue ();
返回值:它返回从队列开头删除的对象。
异常:该方法在调用空队列时引发InvalidOperationException,因此,在调用Dequeue()方法之前,请始终检查队列的总数是否大于零。
以下示例程序旨在说明上述方法的用法:
// C# Program to illustrate the use
// of Queue.Dequeue Method
using System;
using System.Collections;
class GFG {
// Main Method
public static void Main()
{
Queue queue = new Queue();
queue.Enqueue(3);
queue.Enqueue(2);
queue.Enqueue(1);
queue.Enqueue("Four");
Console.WriteLine("Number of elements in the Queue: {0}",
queue.Count);
// Retrieveing top element of queue
Console.WriteLine("Top element of queue is:");
Console.WriteLine(queue.Dequeue());
// printing the no of queue element
// after dequeue operation
Console.WriteLine("Number of elements in the Queue: {0}",
queue.Count);
}
}
输出:
Number of elements in the Queue: 4 Top element of queue is: 3 Number of elements in the Queue: 3
// C# Program to illustrate the use
// of Queue.Dequeue Method
using System;
using System.Collections;
class GFG {
// Main Method
public static void Main()
{
Queue queue = new Queue();
// Adding elements in Queue
queue.Enqueue(2);
queue.Enqueue("Four");
Console.WriteLine("Number of elements in the Queue: {0}",
queue.Count);
// Retrieveing top element of queue
Console.WriteLine("Top element of queue is:");
Console.WriteLine(queue.Dequeue());
// printing the no. of queue element
// after dequeue operation
Console.WriteLine("Number of elements in the Queue: {0}",
queue.Count);
}
}
输出:
Number of elements in the Queue: 2 Top element of queue is: 2 Number of elements in the Queue: 1
参考:
- https://docs.microsoft.com/en-us/dotnet/api/system.collections.queue.dequeue?view=netframework-4.7.2
相关用法
注:本文由纯净天空筛选整理自Twinkl Bajaj大神的英文原创作品 Queue.Dequeue Method in C#。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。