I think you want to use your function get_positive_value()
like this:
withdrawal_amt = get_positive_value();
and similarly others.
You are passing withdrawal_amt
, amount
and other variables mentioned in warnings unintialized.
Note that all the variables declared inside some function are stored in some random memory (stack memory) location which compiler chooses, and that location may contain some garbage value which will be taken as initial value of your variables.
Hence compiler instructs you beforehand to initialize them to some known value, so that you do not get your bank balance -1000.00 USD
when you 'deposited' 1000.00 USD
;-)