1 pragma solidity ^0.4.4; 2  3 contract Person { 4  5     string public  name; 6     uint age; 7     uint private weight; 8     string internal birthday; 9     10     function Person() {11         name = "";12         age = 0;13         weight = 0;14         birthday = "0000-00-00";15     }16  17     function f0()  payable public returns(uint){18         return address(this).balance; // 只要一调用f0,balance就改了，不需要等f0执行结束19     }20     21     function f1() public returns(uint) {22         return address(this).balance; // 调用完f0,再调f1查询合约账户余额，与f0查到的相同23     }