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What is the difference between peek(),poll() and remove() method of the Queue interface?

Both poll() and remove() method is used to remove head object of the Queue.

The main difference lies when the Queue is empty(). If Queue is empty then poll() method will return null . While in similar case , remove() method will throw NoSuchElementException . peek() method retrieves but does not remove the head of the Queue. If queue is empty then peek() method also returns null.

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List and its implementations

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