Example usage for java.util ArrayDeque descendingIterator

Introduction

In this page you can find the example usage for java.util ArrayDeque descendingIterator.

Prototype

public Iterator<E> descendingIterator() 

Source Link

Usage

From source file:Main.java

public static void main(String[] args) {

    ArrayDeque<Integer> deque = new ArrayDeque<Integer>(8);

    deque.add(3);/*from  w  w  w.  j a va 2 s  . c o m*/
    deque.add(4);
    deque.add(25);
    deque.add(1);

    //iterator() is used to print all the elements
    //next() returns the next element on each iteration
    System.out.println("printing elements using iterator:");

    for (Iterator itr = deque.iterator(); itr.hasNext();) {
        System.out.println(itr.next());
    }

    //descendingIterator() is used to print the elements in reverse order
    //next() returns the next element on each iteration
    System.out.println("printing elements in reverse order:");

    for (Iterator descItr = deque.descendingIterator(); descItr.hasNext();) {
        System.out.println(descItr.next());
    }
}

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From source file:com.google.gwt.emultest.java.util.ArrayDequeTest.java

public void testDescendingIterator() {
    Object o1 = new Object();
    Object o2 = new Object();
    Object o3 = new Object();

    ArrayDeque<Object> deque = new ArrayDeque<>();
    Iterator<Object> it = deque.descendingIterator();
    assertFalse(it.hasNext());//  w  w  w. j  a v  a  2  s . co  m
    try {
        it.next();
        fail();
    } catch (NoSuchElementException expected) {
    }

    deque.add(o1);
    deque.add(o2);
    deque.add(o3);
    it = deque.descendingIterator();
    assertTrue(it.hasNext());
    assertEquals(o3, it.next());
    assertTrue(it.hasNext());
    assertEquals(o2, it.next());
    assertTrue(it.hasNext());
    assertEquals(o1, it.next());
    assertFalse(it.hasNext());
    try {
        it.next();
        fail();
    } catch (NoSuchElementException expected) {
    }
    checkDequeSizeAndContent(deque, o1, o2, o3);

    deque = new ArrayDeque<>();
    deque.add(o1);
    deque.add(o2);
    deque.add(o3);
    it = deque.descendingIterator();
    assertTrue(it.hasNext());
    assertEquals(o3, it.next());
    it.remove();
    assertEquals(2, deque.size());
    assertTrue(it.hasNext());
    assertEquals(o2, it.next());
    assertTrue(it.hasNext());
    assertEquals(o1, it.next());
    it.remove();
    checkDequeSizeAndContent(deque, o2);
}

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From source file:com.google.gwt.emultest.java.util.ArrayDequeTest.java

public void testFailFastDescendingIterator() {
    ArrayDeque<Object> deque = new ArrayDeque<>(asList(getFullNonNullElements()));
    Iterator<Object> it = deque.descendingIterator();
    it.next();/*w ww .  ja v  a 2  s.  c  o  m*/
    deque.removeLast();
    try {
        it.next();
    } catch (ConcurrentModificationException e) {
        fail();
    }
    deque.removeFirst();
    try {
        it.next();
        fail();
    } catch (ConcurrentModificationException expected) {
    }

    deque = new ArrayDeque<>(asList(getFullNonNullElements()));
    it = deque.descendingIterator();
    it.next();
    deque.clear();
    try {
        it.next();
        fail();
    } catch (ConcurrentModificationException expected) {
    }

    deque = new ArrayDeque<>(asList(getFullNonNullElements()));
    it = deque.descendingIterator();
    it.next();
    deque.addLast(new Object());
    try {
        it.next();
    } catch (ConcurrentModificationException e) {
        fail();
    }
    deque.addFirst(new Object());
    try {
        it.next();
        fail();
    } catch (ConcurrentModificationException expected) {
    }

    deque = new ArrayDeque<>(asList(getFullNonNullElements()));
    it = deque.descendingIterator();
    it.next();
    it.next();
    deque.removeLast();
    try {
        it.remove();
    } catch (ConcurrentModificationException e) {
        fail();
    }

    deque = new ArrayDeque<>(asList(getFullNonNullElements()));
    it = deque.descendingIterator();
    it.next();
    it.next();
    deque.removeLast();
    deque.removeLast();
    try {
        it.remove();
        fail();
    } catch (ConcurrentModificationException expected) {
    }
}

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