FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.
| pragma solidity >=0.7.0 <0.9.0; | |
| contract Base { | |
| uint public num; | |
| address public sender; | |
| function setNum(uint _num) public { | |
| num = _num; | |
| sender = msg.sender; | |
| } |
| Token | Feature | Known Vulnerabilities | Resources | Examples |
|---|---|---|---|---|
| ERC20 | Allowance | Double withdrawal (front-running) |
| #!/bin/bash | |
| # Input flags | |
| LANG="" | |
| APP_NAME="" | |
| # The directory path must be relative to where the script lives | |
| DIR="" |
| pragma solidity 0.8.0; | |
| // We need some util functions for strings. | |
| import "@openzeppelin/contracts/utils/Strings.sol"; | |
| import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol"; | |
| import "@openzeppelin/contracts/utils/Counters.sol"; | |
| import "hardhat/console.sol"; | |
| contract MyEpicNFT is ERC721URIStorage { |
Using newer compiler versions and the optimizer gives gas optimizations and additional safety checks for free!
The advantages of versions 0.8.* over <0.8.0 are:
0.8.0 (can be more gas efficient than some
library based safemath).0.8.2, leads to cheaper runtime gas.
Especially relevant when the contract has small functions. For