System for bank clients

Question

https://code.sololearn.com/cTw4eQ3PO178/?ref=app
this is the task from sololearn java course , and i absolutely can’t understand the line of code in the end which looks like: while(number != 0);
i tried to change it and there goes an error. can’t understand the sense of it, the mechanism why it must be not equal to 0?? how it works? can anybody explain this thing, i’ve already braked my brain trying to understand this.
when there were exercises it was much more easier like while<5 and there was 1,2,3,4.

Answer 1

thank you for very good explanation! it really helped!