Java Deque iterator()方法

Deque接口 的 iterator() 方法以适当的顺序返回该deque中元素的迭代器。这些元素将按照从头（head）到尾（tail）的顺序返回。返回的迭代器是一个 “弱一致性 “迭代器。

语法

Iterator iterator()

参数： 该方法不接受任何参数。

返回： 该方法以适当的顺序返回该deque中的元素的一个迭代器。

下面的程序说明了Deque的iterator()方法。

程序1： 在 ArrayDeque 的帮助下 。

// Java Program Demonstrate iterator()
// method of Deque
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of Deque
        Deque<Integer> DQ
            = new ArrayDeque<Integer>();
  
        // Add numbers to end of Deque
        DQ.add(7855642);
        DQ.add(35658786);
        DQ.add(5278367);
        DQ.add(74381793);
  
        // Call iterator() method of Deque
        Iterator iteratorVals = DQ.iterator();
  
        // Print elements of iterator
        // created from Deque
        System.out.println("The iterator values"
                           + " of Deque are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出:

The iterator values of Deque are:
7855642
35658786
5278367
74381793

程序2： 在 LinkedList 的帮助下 。

// Java Program Demonstrate iterator()
// method of Deque
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of Deque
        Deque<Integer> DQ
            = new LinkedList<Integer>();
  
        // Add numbers to end of Deque
        DQ.add(7855642);
        DQ.add(35658786);
        DQ.add(5278367);
        DQ.add(74381793);
  
        // Call iterator() method of Deque
        Iterator iteratorVals = DQ.iterator();
  
        // Print elements of iterator
        // created from Deque
        System.out.println("The iterator values"
                           + " of Deque are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出:

The iterator values of Deque are:
7855642
35658786
5278367
74381793

程序3： 在 LinkedBlockingDeque 的帮助下 。

// Java Program Demonstrate iterator()
// method of Deque
import java.util.*;
import java.util.concurrent.LinkedBlockingDeque;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of Deque
        Deque<Integer> DQ
            = new LinkedBlockingDeque<Integer>();
  
        // Add numbers to end of Deque
        DQ.add(7855642);
        DQ.add(35658786);
        DQ.add(5278367);
        DQ.add(74381793);
  
        // Call iterator() method of Deque
        Iterator iteratorVals = DQ.iterator();
  
        // Print elements of iterator
        // created from Deque
        System.out.println("The iterator values"
                           + " of Deque are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出:

The iterator values of Deque are:
7855642
35658786
5278367
74381793

程序4： 在 ConcurrentLinkedDeque 的帮助下 。

// Java Program Demonstrate iterator()
// method of Deque
import java.util.*;
import java.util.concurrent.ConcurrentLinkedDeque;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of Deque
        Deque<Integer> DQ
            = new ConcurrentLinkedDeque<Integer>();
  
        // Add numbers to end of Deque
        DQ.add(7855642);
        DQ.add(35658786);
        DQ.add(5278367);
        DQ.add(74381793);
  
        // Call iterator() method of Deque
        Iterator iteratorVals = DQ.iterator();
  
        // Print elements of iterator
        // created from Deque
        System.out.println("The iterator values"
                           + " of Deque are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出:

The iterator values of Deque are:
7855642
35658786
5278367
74381793

参考资料: https://docs.oracle.com/javase/8/docs/api/java/util/Deque.html#iterator-