Code:

pragma solidity ^0.8.21;
contract HelloWeb3{
    string public _string = "Hello Web3!";
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;
contract HelloWeb3{
    //bool类型

    bool public _bool = true;
    bool public _bool1 = !_bool; // 取非
    bool public _bool2 = _bool && _bool1; // 与
    bool public _bool3 = _bool || _bool1; // 或
    bool public _bool4 = _bool == _bool1; // 相等
    bool public _bool5 = _bool != _bool1; // 不相等

    //当||时，前者true直接true，当&&时前者false直接false
    bool public _bool6 = _bool || _bool1;
    bool public _bool7 = _bool1 && _bool;

    //整型
    int public _int = -1;
    uint public  _uint = 1;
    uint256 public _number = 20220330;

    // 整数运算
    uint256 public _number1 = _number + 1; // +，-，*，/
    uint256 public _number2 = 2**2; // 指数
    uint256 public _number3 = 7 % 2; // 取余数
    bool public _numberbool = _number2 > _number3; // 比大小

    // 地址
    address public _address = 0x7A58c0Be72BE218B41C608b7Fe7C5bB630736C71;
    address payable public _address1 = payable(_address); // payable address，可以转账、查余额
    // 地址类型的成员
    uint256 public balance = _address1.balance; // balance of address

    // 固定长度的字节数组
    bytes32 public _byte32 = "MiniSolidity"; 
    bytes1 public _byte = _byte32[0]; 

    // 用enum将uint 0， 1， 2表示为Buy, Hold, Sell
    enum ActionSet { Buy, Hold, Sell }
    // 创建enum变量 action
    ActionSet action = ActionSet.Buy;

    // enum可以和uint显式的转换
    function enumToUint() external view returns(uint){
        return uint(action);
    }
}

pragma solidity ^0.8.21;

contract FunctionTypes{
    uint256 public number = 5;

    // 默认function
    function add() external{
        number = number + 1;
    }

    // pure: 纯纯牛马
    function addPure(uint256 _number) external pure returns(uint256 new_number){
        new_number = _number + 1;
    }

    // view: 看客
    function addView() external view returns(uint256 new_number) {
        new_number = number + 1;
    }

    // internal: 内部函数
    function minus() internal {
        number = number - 1;
    }

    // 合约内的函数可以调用内部函数
    function minusCall() external {
        minus();
    }

    // payable: 递钱，能给合约支付eth的函数
    function minusPayable() external payable returns(uint256 balance) {
        minus();    
        balance = address(this).balance;
    }
}

view 函数可以读取状态变量，但不能改写；pure 函数既不能读取也不能改写状态变量。