摘要:
select date, count(fail) as fail,count(win) as win from (select date,(case (result) when 'fail' then 'fail' end ) as fail,(case (result) when 'win' th 阅读全文
摘要:
var a = {n: 1};var b = a;a.x = a = {n: 2};这里面第三句可以直接拆解为:a.x = {n : 2};a = {n : 2};a.x 赋值的时候,和b还是引用的同一个内存地址,a赋值的时候,a的内存地址就指向了{n:2},最后a.x是undefined,b.x是 阅读全文