What wrong with this program

Question

It's output should be total sum of array elements but it is printing random long numbers
https://code.sololearn.com/c2ZB6FBSqCHX/?ref=app

Answer 1

Also, it is recommended to initialize <sum> variable by zero to avoid it from garbage value, being uninitialized.

Answer 2

Nikhil You've actually got it the wrong way around, VLAs are legal in C but not standard C++ (although support has become optional since C11 and I would therefore opt for proper dynamic memory allocation either way).
Ipang is right in that the sum variable is simply uninitialized.