A priority-queue is an “abstract data type”. It is similar to a normal queue, but certain elements take priority when they are polled (perhaps for a print statement).
Why do we need priority queues?
Let’s say you’re in the hospital with a sore-throat at midnight. You have waited your turn, and now you are the front of the queue that the emergency staff need to see. There are 5 people behind you with broken bones and 3rd degree burns. This is ultimately where the queue fails in real-life situations.
Namely because someone is likely to pass-away during the time it takes the nurses to source a throat lozenge and a paracetamol for you.
Priority queues allow you prioritise certain elements. Which is great for the people bleeding-out profusely, but not so great for your sore throat.
How Do You Create A Priority Queue In Java?[java] //This creates an empty Priority Queue with the default 11 element capacity.
PriorityQueue exampleQueue = new PriorityQueue();
//This creates a queue with capacity for 5 elements.
PriorityQueue fiveElementQueue = new PriorityQueue(5);
Simple Priority Queue Methods
How to add an Object to a Priority Queue[java] //First create some objects..
String feeling = “sad”;
String not = “popular”;
//Add the objects to it
How to return the front of Priority Queue[java] //This will return the front of the queue without dequeuing (removing) the element.
How return your Priority Queue as an Array[java] //This will return the front of the queue without dequeuing (removing) the element.
How to return the head (the ordered first in the queue; poll)[java] //This will dequeue and return the front of the queue based on priority.