How to do while loops for cashier amount

Question

I want to do while if the cash<total
Will show the message if enough money or need more money from the total... If get what I mean
Example total is 20
U give 10 will show messages that u have to not enough money..if u put 3 will get take way from the total until get 0 will end the while loop

Answer 1

Read on control structure concept