openzeppelin-solidity VS eattheblocks

pragma solidity ^0.5.0; import "https://github.com/OpenZeppelin/openzeppelin-solidity/contracts/math/SafeMath.sol"; contract MyContract { using SafeMath for uint256; function deposit() public payable { // code to deposit ether } function withdraw(uint256 _amount) public { require(this.balance.sub(_amount) >= 0, "Insufficient funds"); // code to withdraw ether } }

The basic structure could be done as follows using OZ ERC20 interface https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/token/ERC20/IERC20.sol

return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { require(b <= a, "SafeMath: subtraction overflow"); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { // Solidity only automatically asserts when dividing by 0 require(b > 0, "SafeMath: division by zero"); uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { require(b != 0, "SafeMath: modulo by zero"); return a % b; }

// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522

Most Uniswap clones on BSC like PancakeSwap, BakerySwap, etc. support flashloans, here's an example contract https://github.com/jklepatch/eattheblocks/tree/master/screencast/310-flashloan-bsc , video explaining usage https://youtu.be/AS_8_C5fTOE

I'm trying to implement a functionality of giving a royalties to the owner after NFTs are sold on the secondary market. As I understand there is no default method or something to give a royalty, so I often see the following solution: https://github.com/jklepatch/eattheblocks/blob/master/screencast/379-nft-royalties/contracts/NFT.sol As I understand I have to pass a token to the constructor of this contract before deploying it. So the question is: if I want to mint and sell NFTs on the Ethereum Mainnet, which token should I pass inside the contract constructor? I see this guy implemented his own token for this purpose, but honestly I don't understand how is it compatible with ETH https://github.com/jklepatch/eattheblocks/blob/master/screencast/379-nft-royalties/contracts/MockToken.sol

The source code is at https://github.com/jklepatch/eattheblocks/tree/master/screencast/223-personal-tokens

EatTheBlocks website or Eattheblocks youtube channel

find other people online who are also coders - you can start with eattheblocks.com (not affiliated or anything but i know the guy loves helping people , he could instead be making millions but instead devotes his time to educating .

EatTheBlocks

u/Sefia Sefia posted two youtube guide on how to create BSC token  (or BEP20 token). There are other youtube guide too. The method of steps are quite similar,  setup Metamask  wallet,  connect to BSC.    copy and paste smart contract,  a software code of  Solidity  like this: https://github.com/jklepatch/eattheblocks/blob/master/screencast/308-create-bep20-token-bsc/Token.sol

Here's a link for building a Compound Dashboard (that project inspired my answer). You can adopt it to cover the Uniswap use case: https://github.com/jklepatch/eattheblocks/tree/master/defi-development-mastery/3-project-compound-dashboard

https://github.com/jklepatch/eattheblocks/tree/master/screencast/195-compound-leveraged-yield-farming