Thread: Use function prototype and function definition in ATM menu

Dear all,

I m a newbie in C. When do the questions in "C Programming for Absolute Beginners" (MICHAEL VINE, 2008)

When talked about structure programming, there is a question.

Write A function that prints an ATM menu—it receives no
parameters and returns no value.


Then i write the following:

Code:

Void displaymenu()
/*********************
Function Prototypes
*********************/
Int display_balance();
Int deposit_funds();
Int transfer_funds();
Int withdraw_funds();
Int get_available_balance();
Int compare_balance_to_request();
Int update_account();
Int disperse_funds();
Int reject_request();
Int print_receipt();
Int verify_ample_funds_exist();
Int initiate_mechanical_process();
Int update_bank_records();
Int atm_lv1() = 0;
Int atm_lv2() =0;
Int atm_lv3() =0;
 
main()
        {
        Do 
                {
                System(“Clear”);
                Printf(“\n\t Welcome to ATM\n\n”);
                Printf(“1\tDisplay Balance\n”);
                Printf(“2\tDeposit Funds\n”);
                Printf(“3\tTransfer Funds\n”);
                Printf(“4\tWithdraw Funds\n”);
                Printf(“5\tQuit\n”);
                Printf(“\n\n Choose number\n”);
                Scanf(“%d”, &atm_lv1);
                Switch(atm_lv1) {
                        Case 1:
                        Int display_balance(); // Suppose another function calling for the account?
                        Printf(“Your Balance is”);
                        Break;
                        Case 2:
                        Int Deposit_funds(); //another interface to detect the amount of banknotes?
                        Break;
                        Case 3:
                        Int Transfer_funds(); //Transfer the amount of fund, enter another account
                        Break;
                        Case 4:
                        Int Withdraw_fund();
                        Break;
                        }
                } while (atm_lv1!=5);
        }// end of ATM level 1
/***************
Function Definition
****************/
//display balance
Int display_balance();
{
        Printf(“Your account balance is”);
}
//disposit fund
Int Deposit_funds();
{
        Printf(“You have deposit to your account”);
}
//transfer fund
Int transfer_funds();
{
        Printf(“You have transferred funds”);
}
//withdraw fund
Int withdraw_funds();
{
        Do 
        {
        System(“Clear”);
        Printf(“\n\t Withdraw funds options \n\n”);
        Printf(“1\tGet Available Balance\n”);
        Printf(“2\tCompare Balance to Request\n”);
        Printf(“3\tUpdate Account\n”);
        Printf(“4\tDisperse Funds\n”);
        Printf(“5\tReject Request\n”);
        Printf(“6\tPrint Receipt\n”);
        Printf(“7\tReturn\n”);
        Printf(“\n\n Choose number\n”);
        Scanf(“%d”, &atm_lv2);
        Switch(atm_lv2) {
                Case 1:
                Int get_available_balance(); 
                Break;
                Case 2:
                Int compare_balance_to_request(); 
                Break;
                Case 3:
                Int update_account (); 
                Break;
                Case 4:
                Int disperse_fund();
                Break;
                Case 5:
                Int reject_request();
                Break;
                Case 6:
                Int print_receipt();
                Break;
                Case 7:
                Int main();
                Break;
                }
        } while (atm_lv2!=8);
}// end of ATM level 2
 
/***************
Function Definition
****************/
//Get available balance
Int get_available_balance();
{
        Printf(“Your available balance is”);
}
//Compare balance to request
Int compare_balance_to_request();
{
        Printf(“Your balance is compared”);
}
//update account
Int update_account();
{
        Printf(“Your account is updated”);
}
//disperse funds
Int disperse_fund(int);
{
Do 
        {
        System(“Clear”);
        Printf(“\n\t Select the Disperse Funds Action”);
        Printf(“1\tVerify Ample Fund\n”);
        Printf(“2\tInitiate Mechanical Process\n”);
        Printf(“3\tUpdate Bank Record\n”);
        Scanf(“%d”,&atm_lv3);
        Switch(atm_lv3){
                Case 1:
                Int verify_ample_funds_exist();
                Case 2:
                Int initiate_mechanical_process();
                Case 3:
                Int update_bank_records();
        } while(atm_lv3!=4);
} //end of atm lv3
//reject request
Int reject_request(int);
{
        Printf(“Your request is rejected”);
}
//print receipt
Int print_receipt();
{
        Printf(“Your receipt is being printed”);
}
//Verify amply funds
Int verify_ample_funds_exist();
{
        Printf(“Your fund is verified”);
}
//initiate mechanical process
Int initiate_mechanical_process();
{
        Printf(“Mechanical process initiated”);
}
//update bank record
Int update_bank_records();
{
        Printf(“Bank records updated”);
}