Program ignores my if/else statements when I run it. Please Help

[patchouli81]

Hi all :) Need help fixing code to calculate male and female body fat percentages. Should a switch structure be used? Please show me what I am doing wrong. Here is what I got:

#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>

using namespace std;

int main()
{
int bodyWeight;
double bodyFatPercent,bodyFat;
double wristM,waistM,hipM,foreArmM;
double a1,a2,a3,a4,a5,b;
string gender;
string female;
string male;

cout << "Enter your body weight: " ;
cin >> bodyWeight;
cout << endl;

cout << "\nEnter your wrist measurement: " ;
cin >> wristM;
cout << endl;

cout << "\nEnter your gender: ";
cin >> female;
cout << endl;

if ( gender == female)
{
cout << "\nEnter your hip measurement: ";
cin >> hipM;
cout << endl;

cout << "\nEnter your waist measurement: ";
cin >> waistM;
cout << endl;

cout << "Enter your forearm measurement: ";
cin >> foreArmM;
cout << endl;

a1 = (bodyWeight * 0.732);
a2 = wristM * 3.140;
a3 = waistM * 0.157;
a4 = hipM * 0.249;
a5 = foreArmM * 0.434;

b = a1 + a2 - a3 - a4 + a5;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

cout << "\nYour body fat percentage is: " <<bodyFatPercent <<endl;
}
else if (gender == male)
{
a1 = (bodyWeight * 1.082) + 94.42;
a2 =wristM * 4.15;

b = a1 - a2;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

cout << "\nYour body fat is: " << bodyFatPercent << endl;
}

system("pause");


return 0;
}

[fizanimtiaz93]

Hey,

maybe this part:

cout << "\nEnter your gender: ";
cin >> female;
cout << endl;

should be:

cout << "\nEnter your gender: ";
cin >> gender;
cout << endl;

Hope that helped.

[patchouli81]

hi thanks for replying. I replaced the part you suggested with :


cout << "\nEnter your gender: ";
cin >> gender;
out << endl;


now the program stops after the user types in their gender. Never evaluated the body percentages.

any other ideas?

[mutexe]

Use code tags.


and change this:
if ( gender == female)
to this:
if ( gender == "female")

and do the same for the male check too.


OR
declare male and female strings like this:

	const string female("female");
	const string male("male");

[upX86]

Hey you are comparing two string variables if ( gender == female) where female is not initialized.

Try this:

string female = "F";
string male = "M";
if ( gender == female)
{
    //
}
else if (gender == male)
{
    //
}

or

if ( gender == "F")
{
    //female
}
else if (gender == "M")
{
    //male
}

[patchouli81]

You guys are awesome. The female calculations are correct. The male calculations are in the negative numbers, which is wrong. Here is my revised code, why is the user getting a negative number for the male calculations ?

#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>

using namespace std;

const string female ("female");
const string male ("male");

int main()
{
int bodyWeight;
double bodyFatPercent,bodyFat;
double wristM,waistM,hipM,foreArmM;
double a1,a2,a3,a4,a5,b;
string gender;
string female;
string male;

cout << "Enter your body weight: " ;
cin >> bodyWeight;
cout << endl;

cout << "\nEnter your wrist measurement: " ;
cin >> wristM;
cout << endl;

cout << "\nEnter your gender: ";
cin >> gender;
cout << endl;

if ( gender == "female")
{
cout << "\nEnter your hip measurement: ";
cin >> hipM;
cout << endl;

cout << "\nEnter your waist measurement: ";
cin >> waistM;
cout << endl;

cout << "Enter your forearm measurement: ";
cin >> foreArmM;
cout << endl;

a1 = (bodyWeight * 0.732);
a2 = wristM * 3.140;
a3 = waistM * 0.157;
a4 = hipM * 0.249;
a5 = foreArmM * 0.434;

b = a1 + a2 - a3 - a4 + a5;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

cout << "\nYour body fat percentage is: " <<bodyFatPercent <<endl;
}
else if (gender == "male")
{
a1 = (bodyWeight * 1.082) + 94.42;
a2 =wristM * 4.15;

b = a1 - a2;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

cout << "\nYour body fat is: " << bodyFatPercent << endl;
}

system("pause");

[/b]
return 0;
}

[MikeyBoy]

Please use code tags when posting code, as mutexe asked you to do.

[patchouli81]

Okay sorry, just that I am super new and had to google what a code tag is. hope this is better. My math calculations are wrong. why? :

b = a1 + a2 - a3 - a4 + a5;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight

correct female percentages outputed

a1 = (bodyWeight * 1.082) + 94.42;
a2 =wristM * 4.15;

b = a1 - a2;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

wrong male percentages( negative number) outputed

[MikeyBoy]

I'd recommend stepping through the calculation code with a debugger. That way you can see exactly what value each variable has at any given point, which should give you an insight into what's going wrong.

My guess would be that b is somehow coming out to be bigger than bodyWeight, so that bodyWeight - b is negative.

[patchouli81]

Im totally stumped. Maybe the book Im reading to produce this code has a bug. I will continue switching numbers around.

[mutexe]

What units are you working in?
Is body weight in tonnes??
Is wrist measurement in millimetres?

I think you should tell the user what units to use when asking them stuff.

[MikeyBoy]

Did you try stepping through the code with a debugger?

[mutexe]

Looks like your 'bodyFat' variable will always be -ve due to the relationship between 'bodyWeight' and 'a1'.

edit:
This line:
a2 =wristM * 4.15;

should use your waist NOT your wrist, if my powers of googling are working.
The male calculation does not use wrist at all I believe.

[patchouli81]

good point. i didn't specify in the code. it would be us units. weight in pounds and wrist measurement in inches :

a1 = (bodyWeight * 1.082) + 94.42;
a2 =wristM * 4.15;

b = a1 - a2;
bodyFat = bodyWeight - b;
bodyFatPercent = bodyFat * 100 / bodyWeight;

getting negative number

[patchouli81]

okay im gonna edit that line mutexe. brb

[mutexe]

no it's not units. read my edit sorry.

you will now need to ask for waist measurement before checking for gender now (as both male and female use it).