For and while loops in Blockchain / Solidity - Mini Project: Build & Apply

Counting Blocks with For and While Loops

📖 Scenario: Imagine you are working with a simple blockchain that stores blocks as numbers. You want to count and display blocks using loops.

🎯 Goal: Build a program that uses both for and while loops to count blocks in a blockchain.

📋 What You'll Learn

Create a list called blocks with the numbers 1 to 5

Create a variable called count and set it to 0

Use a for loop with variable block to iterate over blocks and increase count by 1 each time

Use a while loop to print numbers from 1 up to count

💡 Why This Matters

🌍 Real World

Counting blocks or transactions is common in blockchain programs to track progress or verify data.

💼 Career

Understanding loops is essential for blockchain developers to process data efficiently and automate tasks.

1

Create the blocks list

Create a list called blocks with the numbers 1, 2, 3, 4, and 5.

Blockchain / Solidity

# Create the list blocks with numbers 1 to 5
# Your code here

Need a hint?

Use square brackets [] to create a list with the numbers inside separated by commas.

2

Create the count variable

Create a variable called count and set it to 0.

Blockchain / Solidity

blocks = [1, 2, 3, 4, 5]
# Create a variable count and set it to 0
# Your code here

Need a hint?

Just write count = 0 on a new line.

3

Use a for loop to count blocks

Use a for loop with variable block to iterate over blocks and increase count by 1 inside the loop.

Blockchain / Solidity

blocks = [1, 2, 3, 4, 5]
count = 0
# Use a for loop to increase count by 1 for each block
# Your code here

Need a hint?

Use for block in blocks: and inside the loop write count += 1.

4

Use a while loop to print numbers

Create a variable called i and set it to 1. Use a while loop to print i while it is less than or equal to count. Increase i by 1 each time inside the loop.

Blockchain / Solidity

blocks = [1, 2, 3, 4, 5]
count = 0
for block in blocks:
    count += 1
# Create i = 1 and use a while loop to print i while i <= count
# Increase i by 1 inside the loop
# Your code here

Need a hint?

Start with i = 1. Use while i <= count: and inside print i and then increase i by 1.