Vulnerability blockhash and block.timestamp are not reliable sources for randomness. // SPDX-License-Identifier: MIT pragma solidity ^0.8.10; /* NOTE: cannot use blockhash in Remix so use ganache-cli npm i -g ganache-cli ganache-cli In remix switch env
block对象结构： block.coinbase (address): 当前块的矿工的地址block.difficulty (uint):当前块的难度系数block.gaslimit (uint):当前块gas的上限block.number (uint):当前块编号block.blockhash (function(uint) returns (bytes32)):函数，返回指定块的哈希值，已经被内建函数block
