java - 既然有参构造方法中，参数可以通过new 赋值，为什么还要通过参数赋值给未初始化的成员变量来输出结果？

Question

Answer 1

You are probably talking about assigning values ​​directly when writing fields. This is similar to assigning a value in the constructor. However, writing it directly on the field is generally regarded as the default value. If you need to pass in different values ​​​​according to the situation, you need a constructor.

Answer 2

If you have multiple constructors, and some constructors do not initialize some member variables, then the remaining member variables do not have default values ​​set, something may go wrong