method and the// constructor that accepts an IEnumerable<T>.Queue<string> queueCopy =newQueue<string>(numbers.ToArray()); Console.WriteLine("\nContents of the first copy:");foreach(stringnumberinqueueCopy ) { Console.WriteLine(number); }// Create an array twice the size of the queue ...
This method is similar to theDequeuemethod, butPeekdoes not modify theQueue. nullcan be added to theQueueas a value. To distinguish between a null value and the end of theQueue, check theCountproperty or catch theInvalidOperationException, which is thrown when theQueueis empty. ...
Queue 中 element() 和 peek() 都是用来返回队列的头元素,不删除。 在队列元素为空的情况下,element() 方法会抛出NoSuchElementException异常,peek() 方法只会返回 null。 JDK1.8 中源码解释 /** * Retrieves, but does not remove, the head of this queue. This method * differs from {@link#peek pee...
程序2: 演示Queue空时的peek()方法// Java Program Demonstrate peek() // method of Queue when Queue is empty import java.util.*; public class GFG { public static void main(String[] args) throws IllegalStateException { // create object of Queue Queue<Integer> Q = new LinkedList<Integer>(...
This method is similar to the Dequeue method, but Peek does not modify the Queue. null can be added to the Queue as a value. To distinguish between a null value and the end of the Queue, check the Count property or catch the InvalidOperationException, which is thrown when the Queue is...
[Android.Runtime.Register("peek","()Ljava/lang/Object;","GetPeekHandler:Java.Util.IQueueInvoker, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null")]publicJava.Lang.Object? Peek (); Returns Object the head of this queue, ornullif this queue is empty ...
Peek Method Reference Feedback Definition Namespace: System.Messaging Assembly: System.Messaging.dll Returns a copy of the first message in the queue without removing the message from the queue. Overloads Expand table Peek() Returns without removing (peeks) the first message in the queue...
程序1: 使用peek()方法返回 LinkedBlockingQueue 的头部,其中容量为 7 的 LinkedBlockingQueue 包含名称列表// Java Program Demonstrate peek() // method of LinkedBlockingQueue import java.util.concurrent.LinkedBlockingQueue; public class GFG { public static void main(String[] args) { // define ...
queue is empty. The Peek()// method throws an exception if there is no message// in the queue. This method handles that exception// by returning true to the calling method.//***publicboolIsQueueEmpty(){boolisQueueEmpty =false;// Connect to a queue.MessageQueue myQueue =newMessageQueue...
Returns the object at the beginning of the Queue without removing it. Namespace: System.Collections Assembly: mscorlib (in mscorlib.dll) Syntax C# Copy [MethodImplAttribute(InternalCall)] public virtual Object Peek () Return Value The object at the beginning of the Queue. Version Information ...