Question

*This question was posted earlier but I want to make sure my code differs from the other answer*

CS50 Assignment 3 and Assignment 4 (Both Due By Sunday March 29 11:59 PM) Assignment 3: Bank Application In a recent lecture, we discussed getting input from the user by using the scanf() function. For your reference, I have included a simple example of using scanf() below: scanf() example: #include int main(void) { int number; printf("Enter a number: "); //prompt the user for a number scanf("%d", &number); //store the number the user enters into number printf("%d\n", number); //print out the number that the user entered return 0; } Once you have a good understanding of scanf, please use it to simulate a bank account program.

The program should behave as follows: • Upon startup, the program should ask the user how much money they want to start off with in their bank account as shown here: Welcome to SMC Banking! Thanks for opening an account with us! How much money would you like to start with: • The rest of the examples assume the user entered $1000 for the initial amount. Your program should then prompt the user as so.

Please select from an option below 1. Withdraw 2. Deposit 3. View Balance Enter option: • The user should then enter a 1, 2, or 3 If the user enters a 1 (Withdraw) • Ask them for the amount of money they want to withdraw as shown below: You currently have $1000 Enter amount to withdraw: • If they enter a value less than they currently have in the bank account, subtract it from the amount they have and show them their new balance and end the program as shown below (assume user entered $200 to withdraw): You withdrew $200 Would you like a receipt (y or n): • If user enters y, show them their balance and wish them a great day and end the program Your current balance is $800 Have a great day! • If the user enters n, simply wish them a great day WITHOUT showing them their balance and end the program Have a great day! • HOWEVER IF THE USER TRIES TO WITHDRAW MORE THAN THEY HAVE IN THEIR ACCOUNT, show them the following message and end the program: You have tried to withdraw more than you have, sorry :( Have an OK day! If the user enters a 2 (Deposit) • Show them their current balance and let them enter the amount of money they want to deposit You currently have $1000 Enter amount to deposit: • Then ask if they want a receipt (assume the user deposited $200) Would you like a receipt (y or n): • If user enters y, show them their balance and wish them a great day and end the program Your current balance is $1200 Have a great day! • If the user enters n, simply wish them a great day WITHOUT showing them their balance and end the program Have a great day! If the user enters a 3 (View Balance) • Show the user’s balance Your current balance is $1000 • Ask them if they would like to withdraw, deposit, or quit Please choose an option below: 1. Withdraw 2. Deposit 3. End Transaction Enter option: • If they enter 1 or 2, follow the steps from above for Withdrawing or Depositing, • if they enter 3, simply wish them a great day! Have a great day!

Hints for Assignment 3 It can be helpful to structure your program in a way that matches the assignment description. For example, each option (withdraw, deposit, view balance) have different flows to them that are almost independent but still share some similarities. Seems kind of modular. If I recall correctly, aren’t functions in C also modular…� ? Also, I use the word If A LOT in the assignment description, have we seen if before in C…� ?

Assignment 4: Input Validation Using Loops Input validation is the process of checking the user’s input for a valid value before trying to use the data entered by the user. For example, in the Bank Application above, what should happen if the user tries to enter option 4 which doesn’t exist (Just to remind you, 1 is Withdraw, 2 is Deposit, 3 is View Balance) For this assignment, you should add input validation to your Bank Application such that it makes sure that the user enters only a valid value at each step. Your program should also repeatedly ask the user to enter a value until they enter a valid value. For example, when asking to choose an option, your program should work as follows Please select from an option below 1. Withdraw 2. Deposit 3. View Balance Enter option: 4 Invalid Option Selection Please select from an option below 1. Withdraw 2. Deposit 3. View Balance Enter option: -2 Invalid Option Selection Please select from an option below 1. Withdraw 2. Deposit 3. View Balance Enter option: 3 • Your program should then resume execution as if the user entered 3 correctly the first time (basically start executing the code for View Balance) • You should also perform input validation in ALL places where the user can enter a value as shown below in different examples Example (when selecting an option after viewing balance) Please choose an option below: 1. Withdraw 2. Deposit 3. End Transaction Enter option: 4 Invalid Option Selection Please choose an option below: 1. Withdraw 2. Deposit 3. End Transaction Enter option: -5 Invalid Option Selection Please choose an option below: 1. Withdraw 2. Deposit 3. End Transaction Enter option: a Invalid Option Selection Please choose an option below: 1. Withdraw 2. Deposit 3. End Transaction Enter option: 2 Example (When trying to Withdraw more than I have) You currently have $1000 Enter amount to withdraw: 2000 Insufficient Funds You currently have $1000 Enter amount to withdraw: -5 Invalid Amount You currently have $1000 Enter amount to withdraw: $200 Example (When trying to Deposit Negative Value) You currently have $1000 Enter amount to deposit: -5 Invalid amount Enter amount to deposit: 25 Example (When entering y or n ) You currently have $1000 Would you like a receipt (y or n): b Invalid entry Would you like a receipt (y or n): 97 Invalid entry Would you like a receipt (y or n): y

Hints for Assignment 4 Input validation seems like it repeats asking the user for inputs. Is there something we can use in C that repeats code execution…� ? (The answer is YES)

Answer 1

Assignment 3:

// C program to simulate the banking operation
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
// function declaration
void withdraw(int balance);
void deposit(int balance);
void input_receipt(int balance);

int main()
{
int balance;
int choice;

printf("Welcome to SMC Banking!\nThanks for opening an account with us!");
printf("\nHow much money would you like to start with: ");
scanf("%d",&balance); // input of start balance

// display the menu
printf("\nPlease select from an option below:\n1. Withdraw\n2. Deposit\n3. View Balance");
printf("\nEnter option: ");
scanf("%d",&choice); // input of menu choice

if(choice == 1) // withdraw
{
withdraw(balance);

}
else if(choice == 2) // deposit
{
deposit(balance);

}
else // view balance
{
printf("Your current balance is $%d",balance);
printf("\nPlease select from an option below:\n1. Withdraw\n2. Deposit\n3. End Transaction");
printf("\nEnter option: ");
scanf("%d",&choice);

if(choice == 1)
{
withdraw(balance);

}
else if(choice == 2)
{
deposit(balance);

}else
printf("Have a great day!");
}

return 0;
}

// function to withdraw amount from balance
void withdraw(int balance)
{
int amount;

printf("You currently have $%d. Enter amount to withdraw: ",balance);
scanf("%d",&amount); // input of amount to withdraw

// validate the amount
if(amount < 0 || amount > balance)
printf("You have tried to withdraw more than you have, sorry :(\nHave an OK day!");
else
{
balance -= amount;
printf("You withdrew $%d",amount);
input_receipt(balance);
}
}

// function to deposit amount in balance
void deposit(int balance)
{
int amount;
printf("You currently have $%d. Enter amount to deposit: ",balance);
scanf("%d",&amount);

balance += amount;
printf("You deposited $%d",amount);
input_receipt(balance);
}

// function to print the receipt if the user wants
void input_receipt(int balance)
{
char receipt;
printf("\nWould you like a receipt (y or n): ");
scanf(" %c",&receipt);

if(tolower(receipt) == 'y')
{
printf("Your current balance is $%d",balance);
}
printf("\nHave a great day!");
}

//end of program

Output:

Assignment 4:

// C program to simulate the banking operation
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
// function declaration
void withdraw(int balance);
void deposit(int balance);
void input_receipt(int balance);

int main()
{
int balance;
int choice;

printf("Welcome to SMC Banking!\nThanks for opening an account with us!");
printf("\nHow much money would you like to start with: ");
scanf("%d",&balance); // input of start balance

while(balance < 0)
{
printf("Balance cannot be negative.");
printf("\nHow much money would you like to start with: ");
scanf("%d",&balance);
}

// display the menu
printf("\nPlease select from an option below:\n1. Withdraw\n2. Deposit\n3. View Balance");
printf("\nEnter option: ");
scanf("%d",&choice); // input of menu choice

while(choice < 1 || choice > 3)
{
printf("Invalid option");
printf("\nEnter option: ");
scanf("%d",&choice);
}

if(choice == 1) // withdraw
{
withdraw(balance);

}
else if(choice == 2) // deposit
{
deposit(balance);

}
else // view balance
{
printf("Your current balance is $%d",balance);
printf("\nPlease select from an option below:\n1. Withdraw\n2. Deposit\n3. End Transaction");
printf("\nEnter option: ");
scanf("%d",&choice);

while(choice < 1 || choice > 3)
{
printf("Invalid option");
printf("\nEnter option: ");
scanf("%d",&choice);
}

if(choice == 1)
{
withdraw(balance);

}
else if(choice == 2)
{
deposit(balance);

}else
printf("Have a great day!");
}

return 0;
}

// function to withdraw amount from balance
void withdraw(int balance)
{
int amount;

printf("You currently have $%d. Enter amount to withdraw: ",balance);
scanf("%d",&amount); // input of amount to withdraw

while(amount < 0 || amount > balance)
{
printf("Invalid Amount");
printf("\nYou currently have $%d Enter amount to withdraw: ",balance);
scanf("%d",&amount);
}

// validate the amount
balance -= amount;
printf("You withdrew $%d",amount);
input_receipt(balance);
}

// function to deposit amount in balance
void deposit(int balance)
{
int amount;
printf("You currently have $%d. Enter amount to deposit: ",balance);
scanf("%d",&amount);

while(amount < 0)
{
printf("Invalid Amount");
printf("\nYou currently have $%d Enter amount to deposit: ",balance);
scanf("%d",&amount);
}

balance += amount;
printf("You deposited $%d",amount);
input_receipt(balance);

}

// function to print the receipt if the user wants
void input_receipt(int balance)
{
char receipt;
printf("\nWould you like a receipt (y or n): ");
scanf(" %c",&receipt);

while(tolower(receipt) != 'y' && tolower(receipt) != 'n')
{
printf("Invalid entry.\nWould you like a receipt (y or n): ");
scanf(" %c",&receipt);
}

if(tolower(receipt) == 'y')
{
printf("Your current balance is $%d",balance);
}
printf("\nHave a great day!");
}

//end of program

Output:

Welcome to SMC Banking! Thanks for opening an account with us! How much money would you like to start with: -2000 Balance cannot be negative. How much money would you like to start with: 1000 Please select from an option below: 1. Withdraw 2. Deposit 3. View Balance Enter option: 1 You currently have $1000. Enter amount to withdraw: 2000 Invalid Amount You currently have $1000 Enter amount to withdraw: -200 Invalid Amount You currently have $1000 Enter amount to withdraw: 200 You withdrew $200 Would you like a receipt (y or n): a Invalid entry. Would you like a receipt (y or n): y Your current balance is $800 Have a great day!