solidity ->payable

payable

1.一个函数（或地址）如果想接收ether，需要将其修饰为payable 2.address常用方法 2.1 balance() ->查询当前地址的ether余额 2.2 transfer(uint)->合约向当前地址转指定数量的ether，如果失败会回滚 2.3 send(uint) ->合约向当前地址转指定数量的ether，如果失败会返回false，不回滚（不建议使用send）

// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity ^0.8.9;

contract Payable {
    address payable public owner;

    constructor() payable {
        owner = payable(msg.sender);
    }

    function deposit() public payable {}

    function notPayable() public {}

    function withdraw() public {
        uint amount = address(this).balance;
        owner.transfer(amount);
    }

    function transfer(address payable _to, uint _amount) public {
        _to.transfer(_amount);
    }
}