How do I use realloc in C?

How do I use realloc in C?

You can use realloc to resize a previously allocated memory block. It takes a pointer to the memory block and the new size as arguments.

Can you show me an example of realloc in action?

Sure! Here's a simple example:

int *arr = malloc(5 * sizeof(int));
// ... use arr ...
arr = realloc(arr, 10 * sizeof(int));

What happens if realloc fails?

If realloc fails, it returns NULL and the original memory block remains unchanged. Always check the return value!

Is it safe to use realloc on a NULL pointer?

Yes, if you pass a NULL pointer to realloc, it behaves like malloc and allocates a new memory block.