Java.util.ArrayDeque Class in Java | Set 1
More Methods of util.ArrayDeque Class :
16. 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
17. 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
18. 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
19. 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.
20. 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.
21. 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.
22. 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.
23. 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.
24. 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.
25. pop() : java.util.ArrayDeque.pop() : pops out an element for stack represented by deque
Syntax :
public E pop() Parameters : --------- Return : element at front
26. push(Element e) : java.util.ArrayDeque.push(Element e) : pushes an element onto stack represented by deque
Syntax :
public void push(Element e) Parameters : e : element to be pushed Return : ----------
27. remove() : java.util.ArrayDeque.remove(): returns head element and also removes it
Syntax :
public E remove() Parameters : ------ Return : head of the deque
28. removeFirst() : java.util.ArrayDeque.remove(): returns first element and also removes it
Syntax :
public E removeFirst() Parameters : ------ Return : first element of the deque
29. removeLast() : java.util.ArrayDeque.remove(): returns last element and also removes it
Syntax :
public E removeLast() Parameters : ------ Return : last element of the deque
30. 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
31. 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)
{
// Initializing 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