Programming Notes

Malloc
Malloc is needed in C because sometimes you want memory to be persistent for the life of a program, even when leaving and entering functions and so on. Malloc sets memory aside from the heap and allows it to be persistent until either freed or the program exits. Linked lists need this because we want the information in a list to exist while the main program exists. Arrays allocate space for themselves when they are made, but since they could be local variables then they are more at risk of being lost than if memory is explicitly allocated.

Set the pointer to NULL after free
After freeing anything with free(), set its pointer to NULL.
This may solve some difficult-to-find bugs */