Question

Programming Project #1: Manage Simple Expenses

Objectives:

• Use basic C++ constructs: if, switch, repetition (looping) and functions

• Perform simple data type and string object manipulations

• Solve problem, design solution and implement using C++

Description:

Write a menu-driven program named “ManageSimpleExpenses” that provides the following

options:

1. Earn

2. Spend

3. Show logs

4. Exit

Basically, the program allows the user to enter earning or spending amounts and keep track of

the current balance. It also print out the history of all entries.

Requirements:

1. The program must produce the same output as provided.

2. The user must enter the correct “pin number” which is one of the followings (either 5678

or 8765) in order to start the program.

3. The balance starts at 0

4. There is no need to use array or vector, just simply use string object and string

concatenation to keep track of the entry history.

5. There should be no global variable even the balance and the entry log string must be

local variables and being passed in the parameters.

Required error handling:

The program MUST perform the following checks:

1. Case-insensitive when to ask the user to confirm exiting the program (e.g. accepting both

‘Y’ and ‘y’)

2. Check for bad pin code and allow up to 3 trials.

3. Check for negative amount

4. Check for invalid menu answer

5. Check for spending amount that is greater than the current balance

Answer 1

code :

    #include <iostream>
    #include <string>
    using namespace std;

    // function to earn money
    int earn(int deposit, int balance);

    // function to spend money
    int spend(int withdrawl, int balance);

    // function to track balance
    void showLogs(string logs);

    main(){
        
        // storing account balance
        int balance = 0;
        // storing logs
        string logs = "";


        // flag is for running the program continuosly untill user manually exits.
        // program runs for flag=1 and exists if flag=0
        // logged is used to track user correct pin to avoid re-login 
        // when program starts again
        int flag = 1, logged = 0;
        while (flag == 1){

            // doesn't log if user is already logged
            if (logged == 0){
                
                int pin;
                cout << "Welcome!\nEnter pin:  ";
                cin >> pin;
                // pin check
                if(pin != 5678 && pin != 8765){
                    cout << "Wrong PIN\n";
                    continue;
                }
                logged = 1;
                // prompt menu
                cout << "\nMenu\n1. Earn Money\n2. Spend Money\n3. Show Logs\n4. Exit\n";
            }

            cout << "\nEnter your Option: ";
            int option;
            cin >> option;

            switch (option){
                case 1:
                    cout << "Enter amount to deposit: ";
                    // deposit stores amount user needs to earn
                    // bal stores the balance returned after executing the earn function
                    int deposit, bal;
                    cin >> deposit;
                    bal = earn(deposit, balance);
                    // error if bal is -1, so break without updating balance and logs
                    if(bal == -1)
                        break;
                    // if no error, update original balance and logs
                    balance = bal;
                    logs += "[+] Earned money  ";
                    logs +=  to_string(deposit);
                    logs += "\n";
                    cout << "Succesfully earned money!\n";
                    break;
                case 2:
                    cout << "Enter amount to spend: ";
                    // withdrawl stores amount user needs to spend
                    // bal2 stores the balance returned after executing 
                    // the withdram function
                    int withdrawl, bal2;
                    cin >> withdrawl;
                    bal2 = spend(withdrawl, balance);
                    // error if bal is -1, so break without updating balance and logs
                    if(bal2 == -1)
                        break;
                    // if no error, update original balance and Logs
                    balance = bal2;
                    logs += "[-] Spent money  "; 
                    logs += to_string(withdrawl); 
                    logs += "\n";
                    cout << "Succesfully spent money!\n";
                    break;
                case 3:
                    // showing logs stored in a string
                    cout << logs;
                    // showing the current balance
                    cout << "[=] Current Balance " << balance << "\n";
                    break;
                case 4:
                    // exiting the program
                    // flag made 0 to exit out of the loop to terminate the program
                    flag = 0;
                    // also make logged 0 to log out the user 
                    logged = 0;
                    cout << "Exiting Program!\n";
                    // no other code in this loop below is executed on 
                    // exit and control reaches to start of loop.
                    // this is done using continue
                    continue;
                default:
                    // if no option exits, prompt `invalid option`
                    cout << "Invalid Option! Choose Other\n";
                    break;
            }


        }

    }

    int earn(int deposit, int balance){
        // if deposit amount is negetive raise error by returning -1.
        // return value -1 is handled as error in above program
        if(deposit < 0){
            cout << "Cannot deposit negetive amount\n";
            return -1;
        }
        // update balance and return balance
        balance = balance + deposit;
        return balance;
    }

    int spend(int withdrawl, int balance){
        // if withdrawl amount is negetive raise error by returning -1.
        // return value -1 is handled as error in above program
        if(withdrawl < 0){
            cout << "Cannot widthdraw negetive amount\n";
            return -1;
        }
        // if withdrawl is greater then current balance raise error by returning -1.
        if(withdrawl > balance){
            cout << "No sufficient amount to withdraw\n";
            return -1;
        }
        // update balance and return balance
        balance = balance - withdrawl;
        return balance;
    }

Output:

Have a nice day