Data Structures

Question 1

How would you examine items below the top of a stack?

Answer 1

Use stack.pop() then stack.peek()

Question 2

How would you find out how many items are in a stack?

Answer 2

let items = 0;
while (stack.peek() !== undefiend) {
    stack.pop();
    items++; 
}
return items;

Question 3

How would you examine items after the front of a queue?

Answer 3

queue.peek();

Question 4

How would you cycle through items in a queue without permanently removing them?

Answer 4

let thing = queue.dequeue();
queue.enqueue(thing);