各种加减

来源:互联网 发布:java判断float是否为0 编辑:程序博客网 时间:2024/04/25 07:15
 FALSE + TURE = 1
FALSE + 'str' = 0
TRUE + 'str' = 1
FALSE + 2 = 2
TRUE + 2 = 3
TRUE + NULL = 1
FALSE + NULL = 0
str + NULL = 0
str + 2 = 2
str + 2 = 2
FALSE - TURE = -1
str - TURE = -1
NULL - TURE = -1