solidity 类型强制转换

oraclize result以string格式返回，solidity没有uint(string)这样的强制转换功能，如果要解析其中的数字，可以用oraclize提供的parseInt方法：

pragma solidity ^0.4.21;

import "github.com/oraclize/ethereum-api/oraclizeAPI.sol";

contract StringToUint is usingOraclize{
    string price = "110.42";
    string realStringPrice = "$10.33";
    string badString = "abc";
    uint public priceInt = parseInt(price,2); //11042
    uint public priceIntger = parseInt(price); // 110
    uint public realStringPriceInt = parseInt(realStringPrice,2); //1033
    uint public realStringPriceInteger = parseInt(realStringPrice); //10
    uint public badStringInt = parseInt(badString); //0
    uint public badStringInteger = parseInt(badString,2);   //0 
}