When you are on a PC, there seems to be no difference between assigning an initial value to the pointer and assigning a null value. But there are still some differences. Compared with no initial value, different systems may have different interpretations, so the portability and security of your code are reduced. There may be some errors that are difficult to debug. So generally speaking, assigning an initial value is a good coding habit.

The so-called initialization refers to the values of various parameters (variables) when the system (program) is in the initial state. Because the memory data may be uncertain when the system is reset, initialization (variable assignment, control register assignment configuration, etc. ) is needed at the beginning of the program. Assigning an initial value generally refers to defining a variable and assigning it at the same time.