Solidity Smart Contract Projects

This repository contains multiple smart contracts written in Solidity. These contracts explore the basics of storage, contract creation, inheritance, and real-world applications like ETH-to-USD conversion using Chainlink oracles.

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📦 Included Contracts

1. SimpleStorage.sol

A simple smart contract that allows:

• Storing a single favorite number
• Adding people with their name and favorite number
• Retrieving the stored number or a person's number via name

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2. StorageFactory.sol

This contract uses SimpleStorage to:

• Deploy multiple SimpleStorage contracts dynamically
• Store and retrieve values from specific instances
• Demonstrates contract creation, arrays of contracts, and function forwarding

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3. ExtraStorage.sol

A contract that inherits from SimpleStorage and overrides the store function:

• Adds +5 to whatever value is stored
• Demonstrates inheritance and function overriding in Solidity

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4. PriceConvertor.sol

A Solidity library that:

• Fetches real-time ETH/USD price using Chainlink oracles
• Converts ETH (in wei) to USD
• Can be reused in any contract to apply real-world ETH value checks

📍 Chainlink Price Feed Address Used (Sepolia Testnet): 0x694AA1769357215DE4FAC081bf1f309aDC325306

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🚀 Final Projects

5. FundMe.sol ✅ PROJECT

This is one of the main projects built in this repository.

Features:

• Accepts ETH only if its USD value is greater than $10
• Uses Chainlink oracle for real ETH/USD conversion
• Stores and tracks funders and their contributions
• Includes a withdraw() function restricted to the owner

Concepts Covered:

• Libraries (PriceConvertor)
• Modifiers (onlyOwner)
• Mappings
• Arrays
• Constructor functions

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6. PriceConvertor.sol ✅ PROJECT Helper

This library powers the FundMe contract by converting ETH to USD using Chainlink.

Functions:

• getPrice() – fetch current ETH/USD price
• getConversionRate(ethAmount) – convert ETH to USD
• getVersion() – return oracle version

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🧪 How to Test or Deploy

✅ Remix IDE

All these contracts are fully compatible with Remix:

1. Copy each file into separate tabs
2. Compile using Solidity ^0.8.0
3. Use JavaScript VM or Injected Provider (MetaMask + Sepolia)
4. Deploy and test interactively

✅ Testnet

For FundMe.sol, use Sepolia testnet and grab ETH from:

• Chainlink Faucet
• Alchemy Sepolia Faucet
• https://cloud.google.com/application/web3/faucet/ethereum/sepolia (this is the best source I used)

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🔒 License

MIT License © 2025
Built for learning, experimenting, and deploying real smart contracts using Solidity.

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📬 Connect

Want to collaborate or ask questions? Feel free to reach out!