After following, you can keep track of his dynamic information in a timely manner
Courses in the relevant section：Boolean type Boolean: the simplest and most useful type
true为1； false不是0，但是0可以转为false，空字符串也可以转为false；
2017-07-060个赞
Courses in the relevant section：Integer type: seemingly simple but actually very meaningful
转换成整数false==0；
2017-07-061个赞
