[One to two in C every day] A floating pointer

A daily C array as a parameterEvery day, I picked up a C-language shell, which grew up and formed thousands of miles.
Today's shell: Hanging pointer: Lost pointer, the object pointed to by the pointer is deleted, it becomes a suspended pointer. 1. Example:Since n is defined in the foo function, n is a local variable. n is released after the foo function is completed. When the pointer is used again in the main function, the n pointed to by the pointer has been deleted, so the pointer becomes a floating pointer.2. How to avoid hanging pointers:After the object is deleted, set the pointer to NULL.
Have a nice day!