📚 On-Chain Flashcards (Solidity + Flare Testnet)

🔗 Contract Address

0x73bF4E1220fb69672AaCd80F5e3cecE9B5748Df6
https://coston2-explorer.flare.network/address/0x73bF4E1220fb69672AaCd80F5e3cecE9B5748Df6

---

📝 Project Title

Flashcards — A Simple On-Chain Learning Tool

---

📘 Description

Flashcards is a beginner-friendly decentralized application built on the Flare Coston2 blockchain.
It allows the contract owner to store flashcards — each containing a question and an answer — permanently on-chain.

This project demonstrates how structured data can be added, stored, and retrieved from a smart contract using a clean and minimal Solidity implementation. It is ideal for beginners learning Web3, Solidity, or basic smart contract interactions.

---

🚀 What This Project Does

• Lets the contract owner add study flashcards on-chain
• Stores all flashcards permanently in an array
• Allows anyone to read any card via getCard
• Shows total number of stored flashcards
• Enables a simple UI for interacting with the contract

---

⭐ Features

🔐 Owner-Only Card Creation

Only the wallet that deployed the contract can add flashcards.
This ensures control and prevents spam entries.

📚 On-Chain Flashcard Storage

Every card includes:

• question (string)
• answer (string)

These are stored permanently on the blockchain.

🔍 Easy Retrieval

Anyone can:

• View total flashcards (totalCards)
• Read any flashcard by index (getCard)

🧩 Simple UI Integration

The included frontend:

• Connects via wallet
• Allows adding new flashcards
• Displays total stored cards
• Shows transaction status (pending → confirming → confirmed)
• Handles loading and error states gracefully

👶 Beginner-Friendly Architecture

• No complex logic
• Clean ABI & hook structure
• Minimal contract using structs, arrays, and modifiers

---

💡 How It Solves a Problem

Traditional flashcard tools depend on centralized servers or apps.
This project provides:

✔ Permanent storage

Flashcards stored on-chain can never be removed or lost.

✔ Open access

Anyone can build interfaces or tools on top of the same data.

✔ Educational value

Perfect for teaching:

• Smart contract basics
• On-chain storage patterns
• Access control
• Frontend ↔ blockchain interaction

✔ Expandable foundation

Developers can extend the project with:

• User-generated decks
• Tagging and categorization
• Front-end flashcard viewer
• Gamified learning systems

---

🛠 Included Smart Contract (Solidity)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Flashcards {
    struct Card {
        string question;
        string answer;
    }

    address public owner;
    Card[] public cards;

    constructor() {
        owner = msg.sender;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "Not contract owner");
        _;
    }

    function addCard(string memory _question, string memory _answer) public onlyOwner {
        cards.push(Card(_question, _answer));
    }

    function totalCards() public view returns (uint) {
        return cards.length;
    }

    function getCard(uint index) public view returns (string memory, string memory) {
        require(index < cards.length, "Card does not exist");
        Card memory card = cards[index];
        return (card.question, card.answer);
    }
}