Declaring a regular array size with a variable? I thought not possible.

Question

I've always assumed (from reading books) that when you declare an array e.g "int myarr[10];"...the 10 had to be a literal or a variable declared "const"...so why does this work.
(please input 5 integers.)
(see the array declaration enclosed in "############")
(The code was in response to question on here...removing zeros from user-input)
https://code.sololearn.com/cZBu2O857Jed/#cpp

Answer 1

Initializing an array with a non-constant variable is called "variable length arrays" and is an extension on the C++ language by some compilers.
It is not part of the C++ standard, so this may or may not work on every compiler.
You might as well use an std::vector to get the 'same' results while using proper C++.
In C, however, variable length arrays are part of the standard since C99.

Answer 2

Thank you Dennis...I was a bit surprised it worked (I use code-blocks).
Your suggestion on vectors is exactly what I suggested to the person I original replied to.......but then.... to double-check.....I had a go, and it worked.
Thank you again for your response.