[fenderist]

Okay... I think I know my problem here
tax = rate*income/100;
is not working because I did not set those with specific value
Like: rate(15) or income(4000)
Well... is there any way to make this program so that it would be functional?
I asked my professor for help, but he does not know anymore than I do.

Any help will be apprecated. Save me!
p.s. if you anything related to programming projects from "Problem Solving: The object of programming, 4th edition" by walter savitch, please send it to me.

Result:
Enter the annual income: $4000.00
Enter the state tax rate: 15%
tax rate = 15%
tax = $0.00
net annual income = $4000.00

#include <iostream>
#include <cstdlib>
#include <cctype>
using namespace std;
         
//Class for amounts of money in U.S. currency. 
class Money
{
public:
    friend Money operator +(const Money& amount1, const Money& amount2);

    friend Money operator -(const Money& amount1, const Money& amount2);
    
    friend Money operator *(const Money& amount1, const Money& amount2);
    
    friend Money operator /(const Money& amount1, const Money& amount2);
 
    friend istream& operator >>(istream& ins, Money& the_object);
    
    friend ostream& operator <<(ostream& outs, const Money& a_percent);

    friend bool operator ==(const Money& amount1, const Money& amount2);

    Money(long dollars, int cents);

    Money(long dollars);

    Money( );

    double get_value( ) const;
    double value;

    void input(istream& ins);
    void output(ostream& outs) const;
private:
    long all_cents;
};

int digit_to_int(char c);


int main( )
{
    Money income, tax, total, rate;

    
    cout << "Enter the annual income: ";
    income.input(cin);


    cout << "Enter the state tax rate: ";
    cin >> rate;
      
    cout << "tax rate = ";
    cout << rate;
    
    cout << endl;
    tax = rate*income/100;
    cout << "tax = ";
    tax.output(cout);

    cout << endl;


    cout << "net annual income = ";
    total = income - tax;
    total.output(cout);


    
    int exit;
    cin >> exit;    
    return 0;
}

Money operator -(const Money& amount1, const Money& amount2)
{
    Money temp;
    temp.all_cents = amount1.all_cents - amount2.all_cents;
    return temp;
}

Money operator +(const Money& amount1, const Money& amount2)
{
    Money temp;
    temp.all_cents = amount1.all_cents + amount2.all_cents;
    return temp;
}

Money operator *(const Money& amount1, const Money& amount2)
{
    Money temp;
    temp.all_cents = (amount1.all_cents*amount2.all_cents);
    return temp;
}

Money operator /(const Money& amount1, const Money& amount2)
{
    Money temp;
    temp.all_cents = amount1.all_cents / amount2.all_cents;
    return temp;
}

bool operator ==(const Money& amount1, const Money& amount2)
{
    return (amount1.all_cents == amount2.all_cents);
}


Money::Money(long dollars, int cents)
{
    if(dollars*cents < 0) //If one is negative and one is positive
    {
        cout << "Illegal values for dollars and cents.\n";
        exit(1);
    }
    all_cents = dollars*100 + cents;
}

Money::Money(long dollars) : all_cents(dollars*100)
{
    //Body intentionally blank.
}

Money::Money( ) : all_cents(0)
{
    //Body intentionally blank.
}

double Money::get_value( ) const
{
    return (all_cents * 0.01);
}

//Uses iostream, cctype, cstdlib:
void Money::input(istream& ins)
{
    char one_char, decimal_point,
         digit1, digit2; //digits for the amount of cents
    long dollars;
    int cents;
    bool negative;//set to true if input is negative.
 
    ins >> one_char;
    if (one_char == '-')
    {
        negative = true;
        ins >> one_char; //read '$'
    }
    else
        negative = false;
    //if input is legal, then one_char == '$'

    ins >> dollars >> decimal_point >> digit1 >> digit2;

    if ( one_char != '$' || decimal_point != '.'
         || !isdigit(digit1) || !isdigit(digit2) )
    {
        cout << "Error illegal form for money input\n";
        exit(1);
    }
    cents = digit_to_int(digit1)*10 + digit_to_int(digit2);

    all_cents = dollars*100 + cents;
    if (negative)
        all_cents = -all_cents;
}

//Uses cstdlib and iostream:
void Money::output(ostream& outs) const
{
    long positive_cents, dollars, cents;
    positive_cents = labs(all_cents);
    dollars = positive_cents/100;
    cents = positive_cents%100;

    if (all_cents < 0)
        outs << "-$" << dollars << '.';
    else
        outs << "$" << dollars << '.';

    if (cents < 10)
        outs << '0';
    outs << cents;
}

int digit_to_int(char c)
{
    return ( int(c) - int('0') );
}


istream& operator >>(istream& ins, Money& the_object)
{
         char percent_sign;
         ins >> the_object.value;
         ins >> percent_sign;
         return ins;
         }
ostream& operator <<(ostream& outs, const Money& a_percent)
{
         outs << a_percent.value << '%';
         return outs;
}