Smart contract concept in Blockchain / Solidity - Mini Project: Build & Apply

Smart Contract Concept

📖 Scenario: You are creating a simple smart contract for a blockchain platform. This contract will store and manage a message that anyone can read or update. This is like a digital bulletin board where people can post and change a note.

🎯 Goal: Build a smart contract that stores a message string, allows updating it, and lets anyone read the current message.

📋 What You'll Learn

Create a string variable called message with an initial value

Add a function called setMessage that updates the message

Add a function called getMessage that returns the current message

Print the initial message and the updated message

💡 Why This Matters

🌍 Real World

Smart contracts are programs that run on blockchains to automate agreements and actions without middlemen.

💼 Career

Understanding smart contracts is key for blockchain developers, enabling them to build decentralized apps and services.

1

DATA SETUP: Create the initial message variable

Create a string variable called message and set it to "Hello, Blockchain!".

Blockchain / Solidity

# Create a string variable called message and set it to "Hello, Blockchain!"
# Your code here

Need a hint?

Use a string type variable named message and assign the text inside double quotes.

2

CONFIGURATION: Add a function to update the message

Add a public function called setMessage that takes a string parameter called newMessage and sets message to newMessage.

Blockchain / Solidity

string message = "Hello, Blockchain!";
// Add a public function setMessage(string newMessage) to update message
# Your code here

Need a hint?

Define a public function named setMessage with one string input that assigns the input to message.

3

CORE LOGIC: Add a function to read the message

Add a public function called getMessage that returns the current message string.

Blockchain / Solidity

string message = "Hello, Blockchain!";

public void setMessage(string newMessage) {
    message = newMessage;
}

// Add a public function getMessage() that returns message
# Your code here

Need a hint?

Define a public function named getMessage that returns the message variable.

4

OUTPUT: Display the initial and updated messages

Print the initial message, then call setMessage with "Welcome to Smart Contracts!", and finally print the updated message by calling getMessage.

Blockchain / Solidity

string message = "Hello, Blockchain!";

public void setMessage(string newMessage) {
    message = newMessage;
}

public string getMessage() {
    return message;
}

// Print initial message
// Call setMessage("Welcome to Smart Contracts!")
// Print updated message using getMessage()
# Your code here

Need a hint?

Use System.Console.WriteLine to print messages. Call setMessage with the new text before printing the updated message.