Question

in an effort to only ask what I’m really looking for here… I’m really only concerned if it’s considered bad practice or not to declare an array like below where the size could vary. If it is… I would generally malloc() instead.

void MyFunction()
{

    int size;

    //do a bunch of stuff
    size = 10; //but could have been something else
    int array[size];

    //do more stuff...

}

Answer 1

Generally yes, this is bad practice, although new standards allow you to use this syntax. In my opinion you must allocate (on the heap) the memory you want to use and release it once you’re done with it. Since there is no portable way of checking if the stack is enough to hold that array you should use some methods that can really be checked – like malloc/calloc & free. In the embedded world stack size can be an issue.

If you are worried about fragmentation you can create your own memory allocator, but this is a totally different story.