Java.util.ArrayDeque Class in Java | Set 2

Java.util.ArrayDeque Class in Java | Set 1
More Methods of util.ArrayDeque Class :

offer(Element e) : java.util.ArrayDeque.offer(Element e) : inserts element at the end of deque.
Syntax :

public boolean offer(Element e)
Parameters : 
e - element to add
Return : 
true, if element is added else; false

offerFirst(Element e) : java.util.ArrayDeque.offerFirst(Element e) : inserts element at the front of deque.
Syntax :

public boolean offerFirst(Element e)
Parameters : 
e - element to add
Return : 
true, if element is added else; false

offerLast(Element e) : java.util.ArrayDeque.offerLast(Element e) : inserts element at the end of deque.
Syntax :

public boolean offerLast(Element e)
Parameters : 
e - element to add
Return : 
true, if element is added else; false

peek() : java.util.ArrayDeque.peek(): returns head element without removing it.
Syntax :

public E peek()
Parameters :
--------
Return : 
head of deque or null if deque is empty.

peekFirst() : java.util.ArrayDeque.peekFirst() :returns first element without removing it.
Syntax :

public E peekFirst()
Parameters :
--------
Return : 
first element of deque or null if deque is empty.

peekLast() : java.util.ArrayDeque.peek(): returns last element without removing it.
Syntax :

public E peekLast()
Parameters :
--------
Return : 
Last element of deque or null if deque is empty.

poll() : java.util.ArrayDeque.peek(): returns head element and also removes it
Syntax :

public E poll()
Parameters :
--------
Return : 
head of deque or null if deque is empty.

pollFirst() : java.util.ArrayDeque.peek(): returns first element and also removes it
Syntax :

public E pollFirst()
Parameters :
--------
Return : 
first element of deque or null if deque is empty.

pollLast() : java.util.ArrayDeque.peek(): returns last element and also removes it
Syntax :

public E pollLast()
Parameters :
--------
Return : 
last element of deque or null if deque is empty.

pop() : java.util.ArrayDeque.pop() : pops out an element for stack repesentyed by deque
Syntax :
```
public E pop()
Parameters :
---------
Return : 
element at front
```
push(Element e) : java.util.ArrayDeque.push(Element e) : pushes an element onto stack repesentyed by deque
Syntax :
```
public void push(Element e)
Parameters :
e : element to be pushed
Return : 
----------
```
remove() : java.util.ArrayDeque.remove(): returns head element and also removes it
Syntax :
```
public E remove()
Parameters :
------
Return : 
head of the deque
```
removeFirst() : java.util.ArrayDeque.remove(): returns first element and also removes it
Syntax :
```
public E removeFirst()
Parameters :
------
Return : 
first element of the deque
```
removeLast() : java.util.ArrayDeque.remove(): returns last element and also removes it
Syntax :
```
public E removeLast()
Parameters :
------
Return : 
last element of the deque
```

removeFirstOccurrence(Obj) : java.util.ArrayDeque.removeFirstOccurrence(Obj) : removes the element where it first occur in the deque.
Syntax :

public boolean removeFirstOccurrence(Object obj)
Parameters :
obj : element to be removed
Return : 
true, if the element is removed; else False

removeLastOccurrence(Obj) : java.util.ArrayDeque.removeLastOccurrence(Obj) : removes the element where it last occur in the deque.
Syntax :

public boolean removeLastOccurrence(Object obj)
Parameters :
obj : element to be removed
Return : 
true, if the element is removed; else False

Java Program explaining util.ArrayDeque class methods :

// Java code explaining the use of ArrayDeque class methods 
// offer(), offerFirst(), offerLast(), peek(), peekFirst(), peekLast() 
// poll(), peekFirst(), peekLast(), pop(), push() 
  
import java.util.*; 
public class NewClass 
{ 
    public static void main(String[] args) 
    { 
        // Intializing an deque 
        Deque<Integer> d = new ArrayDeque<Integer>(10); 
  
        // add() method to insert 
        d.add(2); 
        d.add(4); 
  
        // offer() : add element at end 
        d.offer(100); 
        d.offer(101); 
  
        // offerFirst() : add element at start 
        d.offerFirst(1111); 
        d.offerFirst(3333); 
  
        // offerLast() : add element at end 
        d.offerLast(5000); 
        d.offerLast(50001); 
  
        for (Integer element : d) 
        { 
            System.out.println("Element : " + element); 
        } 
  
        // peek() method : to get head 
        System.out.println("\nHead element : " + d.peek()); 
  
        // peekFirst() method : to get First element 
        System.out.println("First element : " + d.peekFirst()); 
  
        // peekLast() method : to get Last element 
        System.out.println("Last element : " + d.peekLast()); 
  
  
        // poll() method : to get head 
        System.out.println("\nHead element poll : " + d.poll()); 
  
        // pollFirst() method : to get First element 
        System.out.println("First element poll : " + d.pollFirst()); 
  
        // pollLast() method : to get Last element 
        System.out.println("Last element poll : " + d.pollLast() + "\n"); 
  
        for (Integer element : d) 
        { 
            System.out.println("Element : " + element); 
        } 
  
        // pop() method : 
        System.out.println("Pop element : " + d.pop()); 
  
        // push() method : 
        d.push(11010101); 
        d.push(121212121); 
        d.push(131313131); 
  
        // remove() method : to get head 
        System.out.println("\nHead element remove : " + d.remove()); 
  
        // removeFirst() method : to get First element 
        System.out.println("First element remove : " + d.removeFirst()); 
  
        // removeLast() method : to get Last element 
        System.out.println("Last element remove : " + d.removeLast() + "\n"); 
  
        for (Integer element : d) 
        { 
            System.out.println("Element : " + element); 
        } 
  
    } 
} 

Output :

Element : 3333
Element : 1111
Element : 2
Element : 4
Element : 100
Element : 101
Element : 5000
Element : 50001

Head element : 3333
First element : 3333
Last element : 50001

Head element poll : 3333
First element poll : 1111
Last element poll : 50001

Element : 2
Element : 4
Element : 100
Element : 101
Element : 5000
Pop element : 2

Head element remove : 131313131
First element remove : 121212121
Last element remove : 5000

Element : 11010101
Element : 4
Element : 100
Element : 101

This article is contributed by Mohit Gupta_OMG 😀. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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