GET 请求时参数都来自 URL，而 URL 都是字符串格式，为了方便操作，可以把字符串格式的参数通过 querystring 转换格式
##字符串转对象
var str = 'firstname=dk&url=http%3A%2F%2Fdk-lan.com&lastname=tom&passowrd=123456'; var param = querystring.parse(param); //结果 //{firstname:"dk", url:"http://dk-lan.com", lastname: 'tom', passowrd: 123456};
var querystring = require('querystring'); var obj = {firstname:"dk", url:"http://dk-lan.com", lastname: 'tom', passowrd: 123456}; //将对象转换成字符串 var param = querystring.stringify(obj); //结果 //firstname=dk&url=http%3A%2F%2Fdk-lan.com&lastname=tom&passowrd=123456