What is the difference between malloc and realloc in C?

What is the difference between malloc and realloc in C?

malloc is used to allocate a specific amount of memory, while realloc is used to resize previously allocated memory.

Can you give me an example of how to use realloc?

Sure! If you initially allocate an array with malloc, you can use realloc to change its size like this:

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

What happens if realloc fails?

If realloc fails, it returns NULL and the original memory block remains unchanged, so you should always check the return value.

Are there any performance considerations when using realloc?

Yes, realloc can be slower if it needs to move the memory block to a new location, especially for large allocations.