Java ArrayDeque clear()方法

java.util.ArrayDeque.clear() 此方法从此双端队列中删除所有元素。

1 语法

public void clear()

2 参数

无

3 返回值

无

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.ArrayDeque.clear()方法的例子
 */
import java.util.ArrayDeque;
import java.util.Deque;

public class Demo {
    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");
    }
}

输出结果为：

Number = 20
Number = 30
Number = 10
Deque consists of 3 elements
Performing clear operation !!
Now, deque consists of 0 elements