DSA · Theory

Difference between Stack and Queue

Theory

67/810

Difference between Stack and Queue

Difference between Stack and Queue is a DSA topic. In plain words you use it for undo typing in a tiny editor. Don’t start with a slogan — start with that picture.

Smallest example: push / pop LIFO. Type it, run it, and say what you see. If you can do that from memory, you know Difference between Stack and Queue.

From the example next to this theory — Difference between Stack and Queue — stack is LIFO: push/pop from the same end.

Trap — pop on empty. Fix that before you talk about advanced DSA.

Viva — what is Difference between Stack and Queue? Then show push / pop LIFO. Then name the trap.

Diagram

    | 3 |  ← top (pop)
    | 2 |
    | 1 |
    LIFO

Exam tip

What is Difference between Stack and Queue? Show this: push / pop LIFO. Trap: pop on empty.

Example

stack = []
stack.append(10)   # push
stack.append(20)
print(stack.pop()) # 20
print(stack[-1])   # peek → 10

Difference between Stack and Queue — stack is LIFO: push/pop from the same end.

Short notes

DefDifference between Stack and Queue — undo typing in a tiny editor.
Rulepush / pop LIFO
Trappop on empty
Usea tiny editor

DSA · Theory

Difference between Stack and Queue

← All stacks

Theory

67/810

Difference between Stack and Queue

Difference between Stack and Queue is a DSA topic. In plain words you use it for undo typing in a tiny editor. Don’t start with a slogan — start with that picture.

Smallest example: push / pop LIFO. Type it, run it, and say what you see. If you can do that from memory, you know Difference between Stack and Queue.

From the example next to this theory — Difference between Stack and Queue — stack is LIFO: push/pop from the same end.

Trap — pop on empty. Fix that before you talk about advanced DSA.

Viva — what is Difference between Stack and Queue? Then show push / pop LIFO. Then name the trap.

Diagram

    | 3 |  ← top (pop)
    | 2 |
    | 1 |
    LIFO

Exam tip

What is Difference between Stack and Queue? Show this: push / pop LIFO. Trap: pop on empty.

Example

stack = []
stack.append(10)   # push
stack.append(20)
print(stack.pop()) # 20
print(stack[-1])   # peek → 10

Difference between Stack and Queue — stack is LIFO: push/pop from the same end.

Short notes

DefDifference between Stack and Queue — undo typing in a tiny editor.
Rulepush / pop LIFO
Trappop on empty
Usea tiny editor

Difference between Stack and Queue

Example

Short notes

Questions

Difference between Stack and Queue

Example

Short notes

Questions