I am compiling the ERC20Basic contract on the Remix, so I receive the token code and I can send BNB for this contract.
However, when I send BNB the function to send me the contract tokens that I created in ERC20Basic is in the DEX contract.
I do not understand how it is possible to do this sending since I compile only the ERC20Basic in Remix, and not DEX.
// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; interface IERC20 { function totalSupply() external view returns (uint256); function balanceOf(address account) external view returns (uint256); function allowance(address owner, address spender) external view returns (uint256); function transfer(address recipient, uint256 amount) external returns (bool); function approve(address spender, uint256 amount) external returns (bool); function transferFrom(address sender, address recipient, uint256 amount) external returns (bool); event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value); } contract ERC20Basic is IERC20{ string public constant name = "ByeSeel"; string public constant symbol = "BYS"; uint8 public constant decimals = 18; //event Approval(address indexed tokenOwner, address indexed spender, uint tokens); //event Transfer(address indexed from, address indexed to, uint tokens); mapping(address => uint256) balances; mapping(address => mapping (address => uint256)) allowed; uint256 totalSupply_ = 10000000 * 10 ** 18; using SafeMath for uint256; constructor() { balances[msg.sender] = totalSupply_; } function totalSupply() public override view returns (uint256) { return totalSupply_; } function balanceOf(address tokenOwner) public override view returns (uint256) { return balances[tokenOwner]; } function transfer(address receiver, uint256 numTokens) public override returns (bool) { require(numTokens <= balances[msg.sender]); balances[msg.sender] = balances[msg.sender].sub(numTokens); balances[receiver] = balances[receiver].add(numTokens); emit Transfer(msg.sender, receiver, numTokens); return true; } function approve(address delegate, uint256 numTokens) public override returns (bool) { allowed[msg.sender][delegate] = numTokens; emit Approval(msg.sender, delegate, numTokens); return true; } function allowance(address owner, address delegate) public override view returns (uint) { return allowed[owner][delegate]; } function transferFrom(address owner, address buyer, uint256 numTokens) public override returns (bool) { require(numTokens <= balances[owner]); require(numTokens <= allowed[owner][msg.sender]); balances[owner] = balances[owner].sub(numTokens); allowed[owner][msg.sender] = allowed[owner][msg.sender].sub(numTokens); balances[buyer] = balances[buyer].add(numTokens); emit Transfer(owner, buyer, numTokens); return true; } event Received(address, uint); receive() external payable { emit Received(msg.sender, msg.value); } } library SafeMath { function sub(uint256 a, uint256 b) internal pure returns (uint256) { assert(b <= a); return a - b; } function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; assert(c >= a); return c; } } contract DEX { event Bought(uint256 amount); event Sold(uint256 amount); IERC20 public token; constructor() { token = new ERC20Basic(); } function buy() payable public { uint256 amountTobuy = msg.value; uint256 dexBalance = token.balanceOf(address(this)); require(amountTobuy > 0, "You need to send some Ether"); require(amountTobuy <= dexBalance, "Not enough tokens in the reserve"); token.transfer(msg.sender, amountTobuy); emit Bought(amountTobuy); } function sell(uint256 amount) public { require(amount > 0, "You need to sell at least some tokens"); uint256 allowance = token.allowance(msg.sender, address(this)); require(allowance >= amount, "Check the token allowance"); token.transferFrom(msg.sender, address(this), amount); payable(msg.sender).transfer(amount); emit Sold(amount); } receive() external payable { buy(); } }
In this case, I just want to send BNB and return my token, but I don't know if I will compile the ERC20Basic contract or the DEX contract.