从 null 中取消装箱整数
Unboxing Integer cast from null
当您执行下面的代码时，i 的值是多少？为什么？
int i = (Integer)null;
见jls5.1.8:
At run time, unboxing conversion proceeds as follows:
...
If r is null, unboxing conversion throws a NullPointerException
当您执行下面的代码时，i 的值是多少？为什么？
int i = (Integer)null;
见jls5.1.8:
At run time, unboxing conversion proceeds as follows:
...
If r is null, unboxing conversion throws a NullPointerException