Java.util.ArrayDeque.clear()方法範例

java.util.ArrayDeque.clear() 方法移除此deque佇列的所有元素。

宣告

以下是java.util.ArrayDeque.clear()方法的宣告

public void clear()

引數

• NA

返回值

此方法不返回任何值。

異常

• NA

例子

下面的範例演示java.util.ArrayDeque.clear()方法的用法。

package com.yiibai;

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");
   }
}   

讓我們來編譯和執行上面的程式，這將產生以下結果：

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