Thread: New to programming, Need help

My instructor asked me to create a conversion program for Temperature conversions, his goal was for us to learn how to use functions outside of the main function/program, otherwise this would have been easier for me I think. Lines 1-64 is my source code, the Last are the errors I receive.

Code:

#include <stdio.h>

void celsius(void); /*The celsius function in main */
void fahrenheit(void); /*The fahrenheit function in main*/
double get_celsius(void); /*Gets celsius temp from user*/
double c2f(double c); /*converts celsius to fahrenheit*/
void printFahrenheit(double f);/*prints the finished conversion*/
double get_fahrenheit(void);/*Gets fahrenheit from user*/
double f2c(double f);/*converts fahrenheit to celsius*/
void printcelsius(double c);/*prints the finished conversion to celsius*/


int main(void) /*Main Program*/
{
        celsius();
        fahrenheit();
        return 0;
    }
    
void celsius(void) /*celsius call function from main*/
{   
    get_celsius();
    c2f(double c);
    printFahrenheit(double f);
    
    }
void fahrenheit(void) /*fahrenheit call function from main*/
{   
    get_fahrenheit();
    f2c(double f);
    printcelsius(double c);
    
    }
double get_celsius() /*Input for C to F conversion*/
{   
    double c;
    printf("Enter a temperature in Celcius for conversion.\n");
    scanf("%lf", &c);
    return 0.0;
}
double c2f(double c) /*Formula for C to F conversion*/
{ double f; 
    f = 32+9/5*c;
    return 0.0;
    }
void printFahrenheit(double f) /*Output for C to F conversion*/
{   printf("Temperature is %f \n", f);
        }
double get_fahrenheit(void) /*Input for F to C conversion*/
{   
    double f;
    printf("Enter a temperature in Fahrenheit for conversion.\n");
    scanf("%lf", &f);
    return 0.0;
    }
double f2c(double f) /*conversion formula from F to C*/
{   c = (f-32)*5/9
    return 0.0;
    }
void printcelsius(double c) /*Output for F to C conversion*/
{
    printf("Temperature is %f \n", c);
    
    }




when I try to compile i get these errors : clang -ansi -pedantic -Wall -Wextra -W -Wmissing-prototypes -Wstrict-prototypes -Wconversion -Wshadow -Wpointer-arith -Wcast-qual -Wcast-align -Wwrite-strings -Wnested-externs -fshort-enums -fno-common -Dinline= -g -DDEBUG -c "pa02.c"
Compilation failed.
pa02.c:27:9: error: expected expression
    c2f(double c);
        ^
pa02.c:28:21: error: expected expression
    printFahrenheit(double f);
                    ^
pa02.c:34:9: error: expected expression
    f2c(double f);
        ^
pa02.c:35:18: error: expected expression
    printcelsius(double c);
                 ^
pa02.c:61:5: error: use of undeclared identifier 'c'
{   c = (f-32)*5/9
    ^
5 errors generated.

My main concern is the "expected expression" errors, any help would be appreciated I've been stuck for hours. Thank you!​

Code:

void fahrenheit(void) /*fahrenheit call function from main*/
{  
    get_fahrenheit();
    f2c(double f); //calling functions means that you must omit the return type and parameter data types.
    printcelsius(double c); //same goes for here.
     
    }

Originally Posted by Click_here

These errors are because you have called the functions incorrectly:





You need to do something more like this:

Code:

double celsiusInput;
double fahrenheitOutput;

celsiusInput = get_celsius();
fahrenheitOutput = c2f(celsiusInput);
printFahrenheit(fahrenheitOutput);

This error is because you have declared 'f' instead of 'c':


You might also want to think about returning the value in 'c' rather than 0.0

Code:

double get_celsius() /*Input for C to F conversion*/
{  
    double c;
    printf("Enter a temperature in Celcius for conversion.\n");
    scanf("%lf", &c);
    return 0.0;
}

Thank you so much, I'll give it another shot in the morning before class. I got lost during the lesson on prototypes and functions so I blame that. I'll come back if I fail still haha