Why this doesnt work?

Question

I really dont understand why it didnt work?someone who knows the ansswer help me
https://code.sololearn.com/WPnsfbcG6Bhr/?ref=app

Answer 1

You are calling the constructor first and then you are taking values from user. When you call constructor initially, it is passing values in a and b which at that moment is undefined.
Therefore, the values in output is undefined.
Take the values from user before calling constructor, your program will run fine then.