Queue (Implementation)

How is Queue implemented in Java? What are some of the main methods that each Queue have? That is what we are going to cover in this lesson.

Implementation of Queues

Queues are implemented in many ways. They can be represented by using an array, a linked list, or even a stack. That being said, an array is most commonly used because it’s the easiest way to implement Queues. A typical Queue must contain the following standard methods:

  • enqueue (datatype V)
  • datatype dequeue()
  • boolean isEmpty()
  • boolean isFull()
  • datatype top()

Before we take a look at these methods one by one, let’s construct a Queue class with an integer data type and create an instance. We will make a class with 5 data members to hold the following information:

  • The array that will contain all the elements
  • The maxSize is the size of this array
  • The front element of the Queue
  • The back element of the Queue
  • The currentSize of elements in the Queue

The code given below shows how to construct the Queue class:

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