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Smart Contract Development

Master writing, testing, and deploying secure blockchain contracts with modern tooling and best practices.

Guide Outline

1. Introduction
2. Environment Setup
3. Writing Contracts
4. Security
5. Deployment

1. Introduction to Smart Contracts

Smart contracts are self-executing agreements with the terms directly written into code. They run on blockchain networks, automatically enforcing and executing contracts without intermediaries.

"Smart contracts are computer protocols intended to digitally facilitate, verify, and enforce the terms of a contract." - Nick Szabo

Why Learn Smart Contracts?

Build decentralized applications (DApps)
Create trustless financial systems
Implement automated business logic

Environment Setup

Install required tools:

npm init -y
npm install hardhat
npm install @nomiclabs/hardhat-ethers @nomicfoundation/hardhat-toolbox

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Hardhat

Development environment, testing framework, and smart contract compilation tools
Solidity

Primary language for writing Ethereum smart contracts

Writing Your First Contract

{`pragma solidity ^0.8.0; contract SimpleStorage { uint storedData; function set(uint x) public { storedData = x; } function get() public view returns (uint) { return storedData; } }`}

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This simple contract stores a number and allows reading it. Solidity syntax resembles JavaScript but compiles to EVM bytecode.

Key Concepts

• State variables store data permanently
• Functions define contract behavior
• View functions read data without changes
• Public functions can be called externally

Security Best Practices

Deploying Contracts

Deployment Script

Create scripts/deploy.js:

async function main() {
  const contractFactory = await hre.ethers.getContractFactory("SimpleStorage");
  const contract = await contractFactory.deploy();
  
  await contract.deployed();
  console.log("Contract deployed to:", contract.address);
}

main()
  .then(() => process.exit(0))
  .catch(error => {
    console.error(error);
    process.exit(1);
  });

Deployment Command

Run deployment:

npx hardhat run scripts/deploy.js --network hardhat

Next Step: Contract Testing

Use npx hardhat test to verify your deployment works as expected.