Thread: Temperature converter program with functions

Originally Posted by GReaper

Right now you're passing the user's choice as a temperature to both functions. I'd take a wild guess and say this isn't what you want... Use a switch statement for the different choices and ask again for the number to pass to them.

By the way, quit_message() returns nothing, you can't assign a void function into anything. You don't need an assignment for that function is what I'm trying to say.

Yeah I want the uset input to be put as the input in either equation. Where would I put the switch statement?

Originally Posted by stahta01

Look up integer division in C.

5/9 equals 0 in C

Tim S.

So as a result I have to use doubles?

Originally Posted by userxbw

are you allowed to use switches yet, what about while loops?
write two functions, one for Celsius, one for Fahrenheit,

Code:

double MyFunction( double input)
{
  return input / 34;
}

that is just an example of a shorter from of doing math in a function and returning it at the same time.

You know what condition loops have to have in order to enter them, you know how to change a variable to make it what you need to have it in order for it to leave a while loop, You know how to use a switch and a char as an int. you know how to use printf and return values from functions together, simultaneously in order to print out the results of the return value, you know how to use printf in general. piece of cake,

one while loop
one switch,
two functions
two vars: 1 char,1 double
and a few printf's for good measure
mixed logically
done.
covers the everything

needing an option to quit most always suggest a loop, if not always (otherwise the program would just process then quit on its own). Some teachers like to be "tricky" sometimes to see who is awake and who is not.
and you need to check your math on the conversions
Temperature Conversion Celsius to Fahrenheit | F to C or C to F | The Old Farmer's Almanac
so you'll end up with something that might look like this

Code:

$ ./Kayla_Hoyte_Temperature_converter
Enter a selection to convert temperatures.
1. Celsius to Fahrenheit
2. Fahrenheit to Celsius.
3. Quit
1
enter temperature in Celsius
-30

Celsius -30.00
Fahrenheit -22.00

Enter a selection to convert temperatures.
1. Celsius to Fahrenheit
2. Fahrenheit to Celsius.
3. Quit
2
enter temperature in Fahrenheit
40

Fahrenheit 40.00
Celsius 4.44

Enter a selection to convert temperatures.
1. Celsius to Fahrenheit
2. Fahrenheit to Celsius.
3. Quit
3

addio

aahahaha I'm really bad at programming, my apologies.

Yes i can use anything else but I have to use at least two functions. Also yes, that's what I'm looking for. How exactly would I add the switch and loops?

Originally Posted by Kayla Hoyte

aahahaha I'm really bad at programming, my apologies.

Yes i can use anything else but I have to use at least two functions. Also yes, that's what I'm looking for. How exactly would I add the switch and loops?

aahahaha you should have practice your loops more.
How would you exactly add a switch and a loop. Let me think.......
you do know that the editors in Computers do have the ability to modify the text you write inside of the file yes?
SO that requires a keyboard. using your keyboard type in the the loop how it is written, same thing for a switch. That's pretty simple, if you do not know how to type ,which you have to else you'd not have been able to post this question.

now apply the rules of trial and error until you get it right, because you should have at least covered loops and a little bit on switches before getting to how to write functions. in order to know how to put them together to write this program.

where would you put the loop and where would you place the switch ? Please show us in here your logic.

Originally Posted by userxbw

aahahaha you should have practice your loops more.
How would you exactly add a switch and a loop. Let me think.......
you do know that the editors in Computers do have the ability to modify the text you write inside of the file yes?
SO that requires a keyboard. using your keyboard type in the the loop how it is written, same thing for a switch. That's pretty simple, if you do not know how to type ,which you have to else you'd not have been able to post this question.

now apply the rules of trial and error until you get it right, because you should have at least covered loops and a little bit on switches before getting to how to write functions. in order to know how to put them together to write this program.

where would you put the loop and where would you place the switch ? Please show us in here your logic.

Yeah, I deserved that.

Moving on, I think I figured it out except the integer division in which I use decimals.

Code:

#include <stdio.h>
#include <stdlib.h>
#define FIRSTCHOICE 1
#define SECONDCHOICE 2
#define THIRDCHOICE 3
/* Write the code using functions. Write a program that gives user menu to choose 
from either convert temperature input from the user in degrees Fahrenheit to degrees
Celsius or convert temperature input from the user in degrees Celsius to degrees
Fahrenheit. Then, another option to quit the program. */
menu_message(int input) {
 
 printf("Choose from the options below(1-3): \n");
 printf("%d. Celsius to Fahrenheit \n", FIRSTCHOICE);
 printf("%d. Fahrenheit to Celsius \n", SECONDCHOICE);
 printf("%d. Quit the program \n", THIRDCHOICE);
}
double celsius_to_fahrenheit(int input) { // Choice 1
 
 double result;
 
 result = (1.8) * input + 32;    
 
 return result;
}
double fahrenheit_to_celsius(int input) { // Choice 2
 
 double result;
 
 result = (.56) * (input - 32);
 
 return result;
}
main() {
 
 int choice, input;
 
 printf("Enter the temperature in Fahrenheit (F) or Celsius (C): \n");
 scanf("%d", &input);
 
 menu_message(input); // Menu to choose from
 scanf("%d", &choice); // Get a value from the user
 switch(choice) {
  case 1:
   printf("The temperature from Celsius to Fahrenheit is: %.1lf", celsius_to_fahrenheit(input));
   break;
  case 2:
   printf("The temperature from Fahrenheit to Celsius is: %.1lf", fahrenheit_to_celsius(input));
   break;
  default:
   printf("Thank you. Goodbye.");
 }
 return 0;
}

Well, at the moment you are doing it the way I prefer anyway - that is to say that the fractional numbers are written out as 1.8 and such. But to trigger decimal division all you have to do is divide decimal numbers: 9.0 / 5.0

now that you got your functions correct, this is how I do mine, just to show you coding styles.

Code:

double celsius_to_fahrenheit(double input) { // Choice 1
    return input * 1.8 + 32;
}
 
double fahrenheit_to_celsius(double input) { // Choice 2
    return  (input - 32) * .5556;
}

Choice three: (f-32)/1.8

just a hint to see if you can figure out how to take what is useful in this code to add it to your other code to make it more teacher friendly and program digestible. (for a lack of a better way of putting it)

Code:

#include <stdio.h>
#include <ctype.h>

int main (void)
{
    printf("Would you like to see a dog chasing his tail? y/n\n");
    
    char what = '\0';
    int whatnow = 0;
    
    scanf(" %c", &what);
    
    while (tolower(what) != 'n')
    {
        printf("I'm chasing my tail\n");
        whatnow++;
        
        if (whatnow == 10)
        {
            printf("Do you still want to see me\nchasing my tail? y/n\n");
        
            if ( (scanf(" %c", &what)) == 'n')
                what = 'q';
            else
                whatnow = 0;
        }
    }
            
    
    
return 0;    
}

just a hint to see if you can figure out how to take what is useful in this code to add it to your other code to make it more teacher friendly and program digestible. (for a lack of a better way of putting it)

So, you purposefully wrote an if statement that is never true?

Code:

(gdb) break 22
Breakpoint 1 at 0x40160b: file userxbw.c, line 22.
(gdb) run
Starting program: C:\Users\jk\Desktop\a.exe
[New Thread 1348.0x5a4]
[New Thread 1348.0x1330]
Would you like to see a dog chasing his tail? y/n
y
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
I'm chasing my tail
Do you still want to see me
chasing my tail? y/n

Breakpoint 1, main () at userxbw.c:22
22                  if ( (scanf(" %c", &what)) == 'n')
(gdb) next
n
25                      whatnow = 0;
(gdb) c
Continuing.
[Thread 1348.0x1330 exited with code 0]
[Inferior 1 (process 1348) exited normally]