How do I define a dynamic array in C

Question

I really don't know how to create a dynamic array in c. This is a quick example. If I define a static array then a buffer overflow is basically set. So How Do I create a dynamic array which I can use in a for loop? Is malloc a good idea? And if it is, how do i use malloc in a for loop?

int my_array[] = {};
int i = 10;
for (i; i <= sizeof(my_array) / sizeof(my_array[0]); i++) {
   my_array[i] = i + 2;
}

This is *undefined behavior*, use either `malloc` or "variable length arrays" (if your compiler supports them) — UnholySheep, Oct 19 '17 at 14:56

score 2 · Answer 1 · answered Oct 19 '17 at 14:58

2

Not only is malloc a good idea, it is the preferred way to dynamically allocate memory in C. The function is defined here, where also an example can be found. Note that free should be used to deallocate the memory once it is not needed anymore.

answered Oct 19 '17 at 14:58

Codor

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Also you must not access the memory after `free`ing it. – Marco Oct 19 '17 at 16:16

How do I define a dynamic array in C

1 Answers1