Stack and Queue Quiz

Which of the following data structure works on Last In First Out (LIFO) principle?

• Queue

• Stack

• Array

• Linked List

Which operation inserts an element into a stack?

• Add

• Enqueue

• Push

• Insert

What is the operation called that removes an element from the top of the stack?

• Delete

• Remove

• Dequeue

• Pop

In a stack, where is the new element added?

• Bottom

• Top

• Middle

• Anywhere

What will be the output after performing operations: push(10), push(20), pop()?

• 10

• 20

• 30

• Error

Which data structure is used for undo operations in text editors?

• Queue

• Array

• Stack

• Tree

What happens when you pop from an empty stack?

• Returns 0

• Inserts null

• Stack Overflow

• Stack Underflow

Which Java class can be used to implement a stack?

• java.util.LinkedList

• java.util.Stack

• java.util.HashMap

• java.util.Array

What is the time complexity of push and pop operations in a stack?

• O(n)

• O(log n)

• O(1)

• O(n log n)

How many stacks are needed to implement a queue?

• 1

• 2

• 3

• None