First Smart Contract Tutorial

Welcome to the first tutorial on smart contracts! In this guide, we will walk you through the basics of creating your first smart contract. Smart contracts are self-executing contracts with the terms of the agreement directly written into lines of code. They run on blockchain networks like Ethereum.

What is a Smart Contract?

A smart contract is a digital agreement that automatically enforces, controls, or documents the performance or terms of an agreement between two or more parties. Once deployed, the contract is immutable and cannot be changed.

Key Features

Automated Execution: Once the conditions are met, the contract automatically executes the terms of the agreement.
Immutability: Once deployed, the contract cannot be altered or deleted.
Transparency: The terms of the contract are visible to all participants.
Security: Smart contracts run on blockchain technology, which is inherently secure.

Setting Up

Before you start writing your smart contract, you need to set up your development environment. Here's a quick rundown:

Install Node.js and npm: These are essential for running and managing your smart contract development tools.
Install Truffle: Truffle is a development framework for Ethereum that provides a suite of tools for smart contract development.
Install Ganache: Ganache is a personal blockchain for testing and developing your smart contracts.

Install Node.js and npm

node -v
npm -v

Install Truffle

npm install -g truffle

Install Ganache

npm install -g ganache-cli

Writing Your First Smart Contract

Let's create a simple smart contract that stores a value. Open your text editor and create a new file called HelloWorld.sol. Here's the code:

pragma solidity ^0.8.0;

contract HelloWorld {
    string public message;

    constructor() {
        message = "Hello, World!";
    }

    function setMessage(string memory newMessage) public {
        message = newMessage;
    }
}

Deploying the Contract

Compile the Contract: Run the following command in your terminal:

truffle compile

Deploy the Contract: Run the following command:

truffle migrate --network development

This will deploy your contract to the development network.

Interacting with the Contract

To interact with your contract, you can use the Truffle console:

truffle console

In the console, you can call the functions of your contract, like this:

await contract.setMessage("Hello, Truffle!");