Learning immediately: https://edu.csdn.net/course/play/9598/204695?utm_source=blogtoedu
int a = 0; // assignment, in fact, is first initialized and then do an assignment
int b {1}; // initialize, more efficient as compared to the above
When the built-in types initialized with a list initialization method, and the initial value of the risk of losing information, the compiler will complain
