I'm trying to create an array of words. What's the difference between creating array like this:
char* myWords[10];
and
char* myWords = malloc(10*sizeof(char *))
I'm assuming that since the first one happens automatically, that the memory is reaped at the end of the function execution. Is that correct?
These are very different types.
The first creates an array of pointers in the usual (automatic) way. The 10 pointers are valid until the function end. They don't point to anything valid with this alone, but can each point to a separate string that can be accessed from each element of the array.
The second allocates a chunk of memory to a single pointer to a character. Thus you would expect it to point to a string (up to 40 or 80 bytes typically). The memory is valid until you free it, but the pointer is automatic just like the first. (Note that an array of character pointers decays to char ** and not char *.)
Yeah, the first one is actually added onto the stack, therefor destroyed once the actual function is returned, and the second one is added onto the heap.
The malloc data is allocated to the heap and the other one to the stack. Malloc puts your data on the heap, which you have to control yourself. After you are done with the data, you should free the data (check the man pages on malloc) so that you don't have memory leaks.
Maybe this website provides you with more insight: http://gribblelab.org/CBootcamp/7_Memory_Stack_vs_Heap.html
