Java.util.ArrayDeque.clear() Java.util.ArrayDeque.addLast() Java.util.ArrayDeque.clone() 描述 所述java.util.ArrayDeque.clear()方法移除此元素的双端队列。 声明 以下是java.util.ArrayDeque.clear()方法的声明 public void clear() 参数 NA 返回值 此方法不返回任何值。 异常 NA 实例 以下示例显示了java.util.ArrayDeque.clear()方法的用法。 package com.tutorialspoint; import java.util.ArrayDeque; import java.util.Deque; public class ArrayDequeDemo { public static void main(String[] args) { // create an empty array deque with an initial capacity Deque<Integer> deque = new ArrayDeque<Integer>(8); // use add() method to add elements in the deque deque.add(20); deque.add(30); deque.add(10); // let us print all the elements available in deque for (Integer number : deque) { System.out.println("Number = " + number); } // finding size of this deque int retval = deque.size(); System.out.println("Deque consists of "+ retval +" elements"); System.out.println("Performing clear operation !!"); deque.clear(); retval = deque.size(); System.out.println("Now, deque consists of "+ retval +" elements"); } } 让我们编译并运行上面的程序,这将产生以下结果 Number = 20 Number = 30 Number = 10 Deque consists of 3 elements Performing clear operation !! Now, deque consists of 0 elements Java.util.ArrayDeque.addLast() Java.util.ArrayDeque.clone()