Sidechains in Blockchain / Solidity - Mini Project: Build & Apply

Sidechains

📖 Scenario: You are working on a blockchain project that uses sidechains to improve scalability and add new features without overloading the main blockchain.Sidechains are separate blockchains linked to the main chain, allowing assets to move between them securely.

🎯 Goal: Build a simple program that simulates transferring tokens from the main blockchain to a sidechain and back.This will help you understand how sidechains work in practice.

📋 What You'll Learn

Create a dictionary to represent the main blockchain balances

Create a dictionary to represent the sidechain balances

Create a variable for the transfer amount

Write code to move tokens from the main chain to the sidechain

Write code to move tokens back from the sidechain to the main chain

Print the final balances on both chains

💡 Why This Matters

🌍 Real World

Sidechains help blockchains handle more transactions and add new features without slowing down the main chain.

💼 Career

Understanding sidechains is useful for blockchain developers working on scalable and flexible blockchain solutions.

1

Create main blockchain balances

Create a dictionary called main_chain_balances with these exact entries: 'Alice': 100, 'Bob': 50, 'Charlie': 75.

Blockchain / Solidity

# Create the main_chain_balances dictionary with exact entries
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys and values.

2

Create sidechain balances and transfer amount

Create a dictionary called sidechain_balances with the same keys as main_chain_balances but all values set to 0. Then create a variable called transfer_amount and set it to 20.

Blockchain / Solidity

main_chain_balances = {'Alice': 100, 'Bob': 50, 'Charlie': 75}
# Create sidechain_balances dictionary with keys 'Alice', 'Bob', 'Charlie' all set to 0
# Create transfer_amount variable set to 20
# Your code here

Need a hint?

Use the same keys as main_chain_balances but set all values to 0 for sidechain_balances.

Set transfer_amount to 20.

3

Transfer tokens from main chain to sidechain

Write a for loop using user to iterate over main_chain_balances. Inside the loop, subtract transfer_amount from main_chain_balances[user] and add transfer_amount to sidechain_balances[user].

Blockchain / Solidity

main_chain_balances = {'Alice': 100, 'Bob': 50, 'Charlie': 75}
sidechain_balances = {'Alice': 0, 'Bob': 0, 'Charlie': 0}
transfer_amount = 20
# Transfer tokens from main_chain_balances to sidechain_balances
# Your code here

Need a hint?

Use a for loop to update balances for each user.

4

Transfer tokens back and print final balances

Write a for loop using user to iterate over sidechain_balances. Inside the loop, add transfer_amount back to main_chain_balances[user] and subtract transfer_amount from sidechain_balances[user]. Then print main_chain_balances and sidechain_balances.

Blockchain / Solidity

main_chain_balances = {'Alice': 100, 'Bob': 50, 'Charlie': 75}
sidechain_balances = {'Alice': 0, 'Bob': 0, 'Charlie': 0}
transfer_amount = 20
for user in main_chain_balances:
    main_chain_balances[user] -= transfer_amount
    sidechain_balances[user] += transfer_amount
# Transfer tokens back from sidechain_balances to main_chain_balances
# Print both dictionaries
# Your code here

Need a hint?

Use a for loop to move tokens back. Then print both dictionaries to see final balances.