我能想到的另外一件事:

One extra thing I can think of:

实例变量具有默认值，即，如果是对象引用，则为null；如果是int，则为0.

Instance variables are given default values, i.e., null if it's an object reference, and 0 if it's an int.

局部变量不会获取默认值，因此需要进行显式初始化(​​并且如果操作失败，编译器通常会抱怨).

Local variables don't get default values, and therefore need to be explicitly initialized (and the compiler usually complains if you fail to do this).