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Solc 0.8.20

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Contracts

5 Built-in

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Local EVM Paris (ChainID: 31337)

Choose Sample ContractSelect a template to explore

📄MyToken.solSolidity ^0.8.20

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

/**
 * @title MyCryptoEduToken
 * @dev Educational ERC-20 Token implementation
 */
contract MyToken {
    string public name = "CryptoEdu Token";
    string public symbol = "EDU";
    uint8 public decimals = 18;
    uint256 public totalSupply = 1000000 * 10 ** 18; // 1,000,000 EDU
    address public owner;

mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Mint(address indexed to, uint256 amount);
    event Burn(address indexed from, uint256 amount);

modifier onlyOwner() {
        require(msg.sender == owner, "Only owner can call this");
        _;
    }

constructor() {
        owner = msg.sender;
        balanceOf[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

function transfer(address to, uint256 amount) public returns (bool) {
        require(to != address(0), "Cannot transfer to zero address");
        require(balanceOf[msg.sender] >= amount, "Insufficient balance");

balanceOf[msg.sender] -= amount;
        balanceOf[to] += amount;

emit Transfer(msg.sender, to, amount);
        return true;
    }

function approve(address spender, uint256 amount) public returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

function transferFrom(address from, address to, uint256 amount) public returns (bool) {
        require(balanceOf[from] >= amount, "Insufficient balance");
        require(allowance[from][msg.sender] >= amount, "Allowance exceeded");

allowance[from][msg.sender] -= amount;
        balanceOf[from] -= amount;
        balanceOf[to] += amount;

emit Transfer(from, to, amount);
        return true;
    }

function mint(address to, uint256 amount) public onlyOwner {
        totalSupply += amount;
        balanceOf[to] += amount;
        emit Mint(to, amount);
        emit Transfer(address(0), to, amount);
    }

function burn(uint256 amount) public {
        require(balanceOf[msg.sender] >= amount, "Insufficient balance to burn");
        balanceOf[msg.sender] -= amount;
        totalSupply -= amount;
        emit Burn(msg.sender, amount);
        emit Transfer(msg.sender, address(0), amount);
    }
}

Build Terminal:Ready to compile

solc v0.8.20+commit.a1b79de6 (EVM Paris)

🎯 What You Learn With This Contract

✓Understand how state variables store token name, symbol, decimals, and total supply
✓Learn how mappings track user token balances without loops
✓Observe how transfer events broadcast state changes to blockchain indexers
✓Test minting new supply and transferring tokens between test accounts without spending real money

💡 Guided Interactive Scenarios

Click any pre-configured test scenario to populate parameters and test contract logic immediately.

Transfer 5,000 EDU to Bob

transfer()

Calls transfer() from Alice to Bob. Check Bob's balance afterward!

Mint 25,000 EDU to Charlie

mint()

Only the deployer (Alice) can mint. See total supply increase from 1,000,000 to 1,025,000.

Burn 1,000 EDU

burn()

Destroys 1,000 tokens from Alice's wallet, reducing circulating supply.

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🎯 What You Learn With This Contract

💡 Guided Interactive Scenarios

Transfer 5,000 EDU to Bob

Mint 25,000 EDU to Charlie

Burn 1,000 EDU

Want to build full-stack decentralized applications?

Smart Contract Playground

ERC-20 Token

ETH Savings Vault

NFT Collectible

DAO Governance & Proposal Voting

Simple Automated Market Maker

🎯 What You Learn With This Contract

💡 Guided Interactive Scenarios

Transfer 5,000 EDU to Bob

Mint 25,000 EDU to Charlie

Burn 1,000 EDU

Want to build full-stack decentralized applications?