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ArrayDeque

• In Java, we can use the ArrayDeque class to implement queue and deque data structures using arrays.
• There are 2 ways to create ArrayDeque
• Non-generic
Syntax:
ArrayDeque arraydeque=new ArrayDeque();
• Generic
Syntax:
ArrayDeque<className> arraydeque=new ArrayDeque<className>();

Note:

• Non-generic ArrayDeque can store Any type of object like Integer, String, Date…etc
• Generic ArrayDeque can store only specify the ClassName.

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ArrayDeque Methods

• void add(value)
• inserts the specified element at the end of the array deque.
• void addFirst(value)
• inserts the specified element at the beginning of the array deque.
• void addLast(value)
• inserts the specified at the end of the array deque .

Notes:If the array deque is full, all these methods add(), addFirst() and addLast() throws IllegalStateException.

• Boolean offer(value)
• inserts the specified element at the end of the array deque.
• Boolean offerFirst(value)
• inserts the specified element at the beginning of the array deque.
• Boolean offerLast(value)
• inserts the specified at the end of the array deque .

Notes:offer(), offerFirst() and offerLast() returns true if the element is successfully inserted, if the array deque is full, these methods return false.

• object getFirst ()
• returns the first element of the array deque.
• object getLast()
• returns the last element of the array deque.
• object peek()
• returns the first element of the array deque.
• object peekFirst()
• returns the first element of the array deque.
• object peekLast()
• returns the last element of the array deque
• object remove()
• returns and removes an element from the first element of the array deque.
• object remove(element)
• returns and removes the specified element from the head of the array deque.
• object removeFirst()
• returns and removes the first element from the array deque.
• object removeLast()
• returns and removes the last element from the array deque.

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