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[Se7Olutionyg]

// program 5: implement a decision structure for the following computation 
# include <iostream>
using namespace std;
//function used
void instruction ();

int main ()
{
    int income, tax,total;
            instruction();

// get the income 
cout << " input your income : $" <<endl;
cin  >> income;


if (income <= 15000)
{
           cout << " Pay no tax " << " your income is "<< income<< endl;
           }
           else if ( 15000 < income <= 44000)
           {
                tax = (income - 15000) * (20/100);
                total = income - tax;
                cout << " Your tax would be 20% on the amount in excess of $15000"<< endl;
                cout << " Your income after tax would be $ " << total << endl ;
                }
           else if ( 44000 < income <= 68150)
           {
                tax = ( 44000 * (22/100) + (income - 44000) * (28/100) );
                total = income - tax;
                cout << " Your income after tax would be $ " << total<< endl ;
                }
           else if ( 68150 < income <= 121300)
           {
                tax = (  58150*(28/100) + (income - 58150) * (31/100));
                total = income - tax;
                cout << " Your income after tax would be $ " << total<< endl ;
                }
           else if (121300< income<= 263750)

           {
                tax = (  121300*(31/100) + (income - 121300) * (36/100));
                total = income - tax;
                cout << " Your income after tax would be $ " << total<< endl ;
                }
             else if ( income> 263750)

           {
                tax = (  263750 *(36/100) + (income - 121300) * (39.6/100));
                total = income - tax;
                cout << " Your income after tax would be $ " << total<< endl ;
                }
system ("pause" );
return total;
return 0;
}
void instruction()

{ 
     cout << "This program compute gross and net salary . " << endl;
     
     }

I checked many times and the program does not have error. how ever, the result is really weird, I dont' know why it doesn't calculate

[grumpier]

All the results it gives are as if tax is zero, right?

The reason is that you're doing everything with integer arithmetic. To look at an example;

else if ( 15000 < income <= 44000)
           {
                tax = (income - 15000) * (20/100);

With integer arithmetic (20 and 100 are integers) 20/100 will be computed as 0 (integer division). (income-15000)*0 will always yield zero.

[Denniz]

Just add a decimal point behind each 100.

[Denniz]

Just notice another problem. Instead of using :

else if ( 15000 < income <= 44000)

you should write it as something like:

else if ( (15000 < income) && (income <= 44000))

instead, for each of the "else-if" statement. Or else, all income greater than 15000 will go into the first "else-if" scope because the compiler will compute (15000 < income) as 1 (true), and then compute (1 <= 44000) as true.

[vmanes]

else if ( (15000 < income) && (income <= 44000))

is more than you need to write.
The use of if...else if... will preclude having to retest for the preceding conditions, so you can simplify the code like

if (income <= 15000)
{
   //do something
}
else if ( income <= 44000 )  //income must be > 15000 in order to get here
{ 
   //do something  else
}
else if ( income <= 68150 )
{ 
  //you get the idea now?
}

And the last condition, where you're testing > 263750, is unnecessary. Just catch that with a final else.

[Se7Olutionyg]

Just add a decimal point behind each 100.

I dont' know if adding a decimal point behind each 100 mean 100.00. or 100.0 , cause I tried but the problem still there. thank you

[Se7Olutionyg]

oh, I got it ,thank you