Medium Mastering Blockchain Part 1

hardhat.config.js

/**
 * @type import('hardhat/config').HardhatUserConfig
 */
module.exports = {
  //Change the code below
  solidity: 0.8.10;
}

HelloContract1.sol

//Code 1
pragma solidity ^0.8.0;

HelloContract2.sol

pragma solidity ^0.8.0;

//Code 2
contract HelloContract {

}

HelloContract3.sol

pragma solidity ^0.8.0;

//Code 2
contract HelloContract {
  function hello() public pure returns (string memory){
    return "Hello, World from Web 3";
  }
}

HelloContract4.sol

//Code 4 
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract HelloContract{
  function hello() public pure returns (string memory){
    return "Hello, world from Web 3";
  }
}