写経の答え

$ npm install @openzeppelin/contracts

$ npm install web3

$ npm install @truffle/hdwallet-provider

code:Token.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract MyToken is ERC20 {

constructor(uint initialSupply) public ERC20 ('MyToken', 'MT'){

_mint(msg.sender, initialSupply);

}

//event setup

event Transfer(address indexed _from, address indexed _to, uint256 _value);

event Approval(address indexed _owner, address indexed _spender, uint256 _value);

//mapping

mapping(address => uint256) public balances;

mapping(address => mapping(address => uint256)) public allowed;

//Transfer function

function send(address _to, uint256 _value) public returns (bool) {

_mint(_to, _value);

return true;

}

//Approve function

function approve(address _spender, uint256 _value) public override returns (bool) {

//allowance

//Approval event

emit Approval(msg.sender, _spender, _value);

return true;

}

//tranferFrom function

function transferFrom(address _from, address _to, uint256 _value) public override returns (bool) {

emit Transfer(_from, _to, _value);

return true;

}

}

code:2_token.sol

var MyToken = artifacts.require("MyToken");

module.exports = function(deployer) {

//Todo:総発行数を設定

const initialSupply = "200000000000000";

deployer.deploy(MyToken,initialSupply,{

gas:3000000

});

};