
Data Structure

This illustrates a data structure, a means of storing data within a program.

You may see other such structures in the Data Structures category.
 Illustration of FIFO behavior
Task

Create a queue data structure and demonstrate its operations.

(For implementations of queues, see the FIFO task.)



Operations:

   push       (aka enqueue) - add element
   pop         (aka dequeue) - pop first element
   empty     - return truth value when empty


See also

 Array
 Associative array: Creation, Iteration
 Collections
 Compound data type
 Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
 Linked list
 Queue: Definition, Usage
 Set
 Singly-linked list: Element definition, Element insertion, List Traversal, Element Removal
 Stack


import "/queue" for Queue
 
var q = Queue.new()
q.push(1)
q.push(2)
System.print("Queue contains %(q)")
System.print("Number of elements in queue = %(q.count)")
var item = q.pop()
System.print("'%(item)' popped from the queue")
System.print("First element is now %(q.peek())")
q.clear()
System.print("Queue cleared")
System.print("Is queue now empty? %((q.isEmpty) ? "yes" : "no")")