By Rolo on Nov 26, 2009This is my solution to Chapter 5 exercise 8 of "C Primer Plus: 5th Edition"
Aside from that, it's a handy program to have around, as temperature conversions always annoy me for some reason.
As the book title implies, this is a C program (hawkee doesn't give a C platform option).
Compile and run with your favorite C compiler. It converts from fahrenheit to celsius and kelvin, then displays all 3 values in float format with .2 precision.
#include <stdio.h>
void Temperatures(double n);
int main() {
double temperature;
printf("Enter a temperature in Fahrenheit: ");
while (scanf("%lf", &temperature) == 1) {
Temperatures(temperature);
printf("Enter a temperature in Fahrenheit (a non-number to quit): ");
}
return 0;
}
void Temperatures(double fahrenheit) {
const double CELSIUS1 = 1.8;
const double CELSIUS2 = 32.0;
const double KELVIN1 = 273.15;
double celsius, kelvin;
celsius = fahrenheit * CELSIUS1 + CELSIUS2;
kelvin = celsius + KELVIN1;
printf("Fahrenheit: %.2lf\n", fahrenheit);
printf("Celsius: %.2lf\n", celsius);
printf("Kelvin: %.2lf\n", kelvin);
}
@Rolo Thanks a lot for the code. I'm on this exercise, figured everything out except for how to get the while loop to quit when a non-numeric value is entered. I took your while loop arguments and they work but could you explain HOW they work? It seems to be checking that the user input is equal to "1" but how does that work when a user doesn't enter a "1"? Thanks.
Probably should've commented with this when I posted the snippet, here's the guidelines for the programming exercise:
8)
Write a program that requests the user to enter a Fahrenheit temperature. The program should read the temperature as a type double number and pass it as an argument to a user-supplied function called Temperatures(). This function should calculate the Celsius equivalent and the Kelvin equivalent and display all three temperatures with a precision of two places to the right of the decimal. It should identify each value with the temperature scale it represents. Here is the formula for converting Fahrenheit to Celsius:
Celsius = 1.8 * Fahrenheit + 32.0
The Kelvin scale, commonly used in science, is a scale in which 0 represents absolute zero, the lower limit to possible temperatures. Here is the formula for converting Celsius to Kelvin:
Kelvin = Celsius + 273.16
The Temperatures() function should use const to create symbolic representations of the three constants that appear in the conversions. The main() function should use a loop to allow the user to enter temperatures repeatedly, stopping when a q or other nonnumeric value is entered.
Remove all 3 constants, as they're not needed in this short of code. A numeric value that is hard-coded isn't going to change. Now if you just used a double NAME, then it might change. So for the Temperature function:
void Temperatures(double fahrenheit) {
double celsius, kelvin;
celsius = fahrenheit * 1.8 + 32.0;
kelvin = celsius + 273.15;
printf("Fahrenheit: %.2lf\n", fahrenheit);
printf("Celsius: %.2lf\n", celsius);
printf("Kelvin: %.2lf\n", kelvin);}