First smart contract deployment in Blockchain / Solidity - Mini Project: Build & Apply

First smart contract deployment

📖 Scenario: You want to create a simple smart contract on the Ethereum blockchain that stores a number and allows you to update it.

🎯 Goal: Build and deploy a basic smart contract that stores a number and lets you change it.

📋 What You'll Learn

Create a smart contract named SimpleStorage

Add a state variable storedNumber of type uint

Write a function setNumber that updates storedNumber

Write a function getNumber that returns storedNumber

Deploy the contract and call getNumber to see the stored value

💡 Why This Matters

🌍 Real World

Smart contracts are programs that run on blockchains to automate agreements and store data securely.

💼 Career

Understanding how to write and deploy smart contracts is essential for blockchain developers and jobs in decentralized finance (DeFi) and NFTs.

1

Create the smart contract and state variable

Write a Solidity contract named SimpleStorage with a public state variable storedNumber of type uint initialized to 0.

Blockchain / Solidity

// Your code here

Need a hint?

Start by declaring the contract and a public unsigned integer variable initialized to zero.

2

Add a function to update the stored number

Inside the SimpleStorage contract, add a public function named setNumber that takes a uint parameter called newNumber and sets storedNumber to newNumber.

Blockchain / Solidity

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint public storedNumber = 0;

    // Your code here
}

Need a hint?

Write a function that takes a number and updates the storedNumber variable.

3

Add a function to read the stored number

Inside the SimpleStorage contract, add a public view function named getNumber that returns a uint and returns the value of storedNumber.

Blockchain / Solidity

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint public storedNumber = 0;

    function setNumber(uint newNumber) public {
        storedNumber = newNumber;
    }

    // Your code here
}

Need a hint?

Create a function that returns the current stored number without changing state.

4

Deploy and test the contract

Deploy the SimpleStorage contract on a test network or local blockchain. Then call setNumber(42) and afterwards call getNumber() to print the stored number.

Blockchain / Solidity

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint public storedNumber = 0;

    function setNumber(uint newNumber) public {
        storedNumber = newNumber;
    }

    function getNumber() public view returns (uint) {
        return storedNumber;
    }
}

// After deployment, call setNumber(42) and then getNumber() to see the result
// Your code here

Need a hint?

Use Remix IDE or a local blockchain like Hardhat to deploy and test your contract. Call setNumber(42) then getNumber() to see 42.