Why stacks follow LIFO principle in Data Structures Theory - See It in Action

Why stacks follow LIFO principle

📖 Scenario: Imagine you have a stack of plates in your kitchen. You always add a new plate on top and take the top plate when you need one.

🎯 Goal: Understand why stacks follow the Last In, First Out (LIFO) principle by relating it to a real-life example and building a simple representation.

📋 What You'll Learn

Create a list called plates with three plate names in order: 'Plate1', 'Plate2', 'Plate3'

Create a variable called top_plate to represent the plate on top of the stack

Use list methods to remove the top plate from plates and assign it to top_plate

Add a new plate called 'Plate4' on top of the stack

💡 Why This Matters

🌍 Real World

Stacks help organize items where only the most recent addition is accessed first, like plates, books, or browser tabs.

💼 Career

Understanding stacks and LIFO is important for programming tasks such as managing function calls, undo operations, and parsing expressions.

1

Create the initial stack of plates

Create a list called plates with these exact items in order: 'Plate1', 'Plate2', 'Plate3'

Data Structures Theory

# Create the list plates with 'Plate1', 'Plate2', 'Plate3'
# Your code here

Need a hint?

Use square brackets to create a list and separate items with commas.

2

Identify the top plate on the stack

Create a variable called top_plate and set it to the last item in the plates list to represent the plate on top

Data Structures Theory

plates = ['Plate1', 'Plate2', 'Plate3']
# Assign the last plate in plates to top_plate
# Your code here

Need a hint?

Use negative indexing to get the last item in a list.

3

Remove the top plate from the stack

Use the pop() method on plates to remove the top plate and assign it to top_plate

Data Structures Theory

plates = ['Plate1', 'Plate2', 'Plate3']
top_plate = plates[-1]
# Remove the top plate from plates and assign it to top_plate
# Your code here

Need a hint?

The pop() method removes and returns the last item in a list.

4

Add a new plate on top of the stack

Use the append() method to add 'Plate4' on top of the plates stack

Data Structures Theory

plates = ['Plate1', 'Plate2', 'Plate3']
top_plate = plates.pop()
# Add 'Plate4' on top of plates
# Your code here

Need a hint?

The append() method adds an item to the end of a list.