看不懂这两行代码啊 请教下
这两句看不懂 if判断是否定义常量 如果定义了下面代码就不执行了？？ 还有下面又定义常量 第二个if是否永远都是失效的？？？？
回复讨论(解决方案)
对！判断是否定义常量 如果定义了下面代码就不执行
第二个if不会用于失效的，当你的is_login()返回false的时候就生效了
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