C++，初始化一个成员变量，最好的方法是定义时初始化，还是在构造函数中初始化？

Question

感觉在构造函数中初始化会有大量的代码，如果成员变量很多的话。。。

Answer 1

You can refer to the "CPP Core Guidelines" recently written by Bjarne Stroustrup, which is mentioned in Article C.48:

Prefer in-class initializers to member initializers in constructors for constant initializers

The conclusion is to give priority to putting it in in-class, that is, initialize it when the members are defined. Because if there are multiple constructors, it may cause inconsistencies and some easy misunderstandings. Detailed answers can be found here.

Answer 2

It depends on the specific context. Generally speaking, I suggest that the storage application be initialized when it is defined.
Other single Init function