 Simple C++ Error

#1 Pooch

Pooch

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Posted 29 August 2009 - 03:27 PM

Hey guys, I am working on my first C++ program for school. For some reason I am getting the following error when I try to compile it:

`truncate' undeclared (first use this function)

Source:

#include <iostream>
#include <math.h>

using namespace std;

#define CENTIMETERS_IN_INCH 2.54
#define POUNDS_IN_KILOGRAM 2.2

int main() {
double feet, inches, centimeters, weight_in_kg, weight_in_lbs;

// get height in feet and inches
cout << "Enter height (feet): ";
cin >> feet;
cout << "Enter (inches): ";
cin >> inches;

// convert feet and inches into centimeters
centimeters = ((12 * feet) + inches) * CENTIMETERS_IN_INCH;

// round 2 decimal places and truncate
centimeters = truncate(centimeters);

printf("Someone that is %g' %g\" would be %g cm tall", feet, inches, centimeters);

// weights for bmi of 18.5
weight_in_kg = truncate(18.5 * centimeters);
weight_in_lbs = round(weight_in_kg * POUNDS_IN_KILOGRAM);

printf("18.5 BMI would correspond to about %g kg or %g lbs", weight_in_kg, weight_in_lbs);

// weights for bmi of 25
weight_in_kg = truncate(25 * centimeters);
weight_in_lbs = round(weight_in_kg * POUNDS_IN_KILOGRAM);

printf("25.0 BMI would correspond to about %g kg or %g lbs", weight_in_kg, weight_in_lbs);

// pause output
cin >> feet;

return 0;
}

// round result
double round(double d) {
return floor(d + 0.5);
}

// round and truncate to 1 decimal place
double truncate(double d) {
return round(double * 10) / 10;
}

Any help would be appreciated. Thanks.

#2 rc69

rc69

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Posted 31 August 2009 - 09:29 AM

C/C++ cares about the order in which you declare things. A function/variable must be declared before it is referenced (it can be defined elsewhere though).

Ref: http://www.cplusplus...ons2/#declaring

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