小米面试.md

1.一个变长数组[1-1000000],用foreach 跟for哪个效率更高 (单链表) 2.mysql tinyint(2) 能存100么 取值范围是多少 3.有一个表: int id varchar code index(id,code) select * from test where id = 12 and code like "%122" select * from test where id = 12 and code like "122%" select * from test where id = 12 and left(code,2) like "122" 以上三个Sql分别会命中索引么 4.php中trait 有什么好处？ 5.