stacks and queues

Question 1

What is a stack?

Answer 1

A LIFO (‘last in first out’) data structure, where items can only be removed from and added to the top of the list.

Question 2

Give an example of where stacks may be used.

Answer 2

• Back button in a web page
• Undo buttons

Question 3

What is a queue?

Answer 3

A FIFO (‘first in first out’) data structure, where items are added to the end of the queue and removed from the front of the queue.