Dynamically allocate array without malloc & calloc

Question

printf("Enter number of elements\n");
scanf("%d",&n);
int num[sizeof(int)*n];

Is this a right way to dynamically allocate array size?

Answer 1

The informal term dynamic allocation almost certainly refers to the formal term allocated storage , meaning heap memory returned from malloc / calloc / realloc .

Sure, there's other "dynamic things" around, like a stack which dynamically grows and sink, but we don't call stack allocation dynamic allocation.

Therefore it is impossible to do dynamic allocation without malloc / calloc / realloc .

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What you have in your example is a variable-length array (VLA). They are allocated in run-time, typically on the stack. You use it incorrectly. You should

1. Verify that n is a valid value within a certain range 1 to max, before creating the array.
2. Allocate the VLA with int num[n]; .