Thread: Caculation Problem

Hello

I'm currently working on a program that when you input a number in Kelvin, it will give u the temperature in either Farenheit or Celcius then tell you what state its in (liquid, solid, gas)

Code:

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

double readnumber(void)
{
	char ch[10];
	double input;
	printf("\n");
	printf("Enter a temperature in Kelvin:\n");
	fflush(stdout);
	fgets(ch,sizeof ch,stdin);
	input=atof(ch);
	return(input);
}

int temptype(void)
{
	char ch[10];
	char option;
	do {
	printf("\n");
	printf("Enter 'F' for Fahrenheit or 'C' for Celcius:\n");
	option=getch();
	option=tolower(option);
	}while(!((option == 'f')||(option == 'c')));
	return(option);
}

int fahrenheit(input)
{

	double inpF;
	int type;
	inpF=((9*(input-273))/5)+32;
	if (inpF>=212) type = 4;
	else if (inpF>=33 && inpF<=211) type = 5;
        else if (inpF<=32) type = 6;
	return(type);
}

int celcius(input)
{
	double inpC;
	int type;
	inpC=input-273;
	if (inpC>=101) type = 1;
	else if (inpC>=1 && inpC <= 100) type = 2;
        else if (inpC<=0) type = 3;
	return(type);
}

int main(void)
{
    int type;
	double input=0.0;
	char option, opt;

        printf("This is the temperature program!");
        do
	{
	     printf("\n\nDo you wish to continue? (y/n): ");
	     	do
	        {
	     	opt = getch();
	        opt = tolower (opt);
	        }while (!((opt=='y')||(opt=='n')));
	        printf("%c\n",opt);
                if (opt=='y')
		{
                   input = readnumber();
                   option = temptype();
                   if(option == 'c')
                   {
                        type = celcius(input);
                   }
                   else if(option == 'f')
                   {
                        type = fahrenheit(input);
                   }
                        switch (type)
			{
		  	case 1:
				 printf("\nThe state of the water is: Gas, at %.2f degrees Celcius.\n", input);
				 break;
		  	case 2:
				 printf("\nThe state of the water is: Liquid, at %.2f degrees Celcius.\n", input);
				 break;
		 	case 3:
				 printf("\nThe state of the water is: Solid, at %.2f degrees Celcius.\n", input);
				 break;
	          	case 4:
	                 	 printf("\nThe state of the water is: Gas, at %.2f degrees Fahrenheit.\n", input);
	                 	 break;
	          	case 5:
	                 	 printf("\nThe state of the water is: Liquid, at %.2f degrees Fahrenheit.\n", input);
	                 	 break;
	          	case 6:
	                 	 printf("\nThe state of the water is: Solid, at %.2f degrees Fahrenheit.\n", input);
	                 	 break;
			}
		}
	}
	while (opt!='n');
	return(0);
}

atm though, it doesn't matter what temperature it is, it will always be a solid and then always end up being the same answer, every time when I go to repeat the loop

First, are you getting good input in readnumber(), specifically in the variable named input?

Second, are you getting good returns from your functions, one by one?

All you need is a print statement at the end of each function to find out which function is bad.

Troubleshooting a program like yours is not hard, and it's a skill you should be practicing.

I don't see errors in the code, but it's late. My guess is that atof() in readnumber(), is getting goofed up by the newline or end of string char that fgets() has put into your char string. Just a guess though.

If so, just use a small for loop from strlen(ch) to 0, (decrementing the index each time through the loop), and remove them.

That's a nice program, but don't let your troubleshooting skills lay dormant. You'll need them, as long as you program.

ok!

thanks for help guys! Its starting to work a lot better now