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 Dequeimport 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:785564235658786527836774381793

程序2： 在 LinkedList 的帮助下 。

// Java Program Demonstrate iterator()// method of Dequeimport 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:785564235658786527836774381793

程序3： 在 LinkedBlockingDeque 的帮助下 。

// Java Program Demonstrate iterator()// method of Dequeimport 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:785564235658786527836774381793

程序4： 在 ConcurrentLinkedDeque 的帮助下 。

// Java Program Demonstrate iterator()// method of Dequeimport 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:785564235658786527836774381793

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