Question

What happens if your program tries to access an array element with an out-of-range subscript?

Answer 1

For different programming languages different events willhappen:
Access violation and program termination for programs in C++, Delphi, Pascal
Out of index exception for OO languages: Java, C#, Python etc.
Another situation with PHP and Javascript: in these languages operator of
reading by index will return an empty value (Null, None, NoN, undefined etc)