What is the value of an index of an array when not given anything?

Question

if you build - int arr[ ] = new arr [5]
and you don't put anything inside does the index 2 (for example) equal to zero??

Answer 1

yes, it is

the correct instruction for dynamic memory allocate is:
int* arr = new int[5];

be careful, this allocated block of memory will not be freed until you tell it so by writing

delete [] arr;

Answer 2

thanks