Thread: slightly stuck with C code

Hey guys im having a bit of trouble compiling my code. I dont know where im going wrong.. Can anyone please help me out?
the error codes im getting are:
Error E2109 lab8.c 68: Not an allowed type in function readType.
Error E2109 lab8.c 71: Not an allowed type in function readType.
Error E2193 lab8.c 82: Too few parameters in call to 'readTemp' in function main.
Error E2193 lab8.c 83: Too few parameters in call to 'readType' in function main.

Code:

#include <stdio.h>
/*
This program is designed to convert kelvin into
fahrenhiet or celsius.
*/




void convertC(int kelvin, int celsius)
{
    (celsius = (kelvin - 273));
     if(celsius < 1)
        {
            printf("The water is in a solid state at %d degrees celsius.\n", celsius);
        }
        else if(celsius > 0 && celsius < 100)
        {
            printf("The water is in a liquid state at %d degrees celsius.\n", celsius);
        }
        else
        {
            printf("The water is in a gas state at %d degrees celsius.\n", celsius);
        }
}
void convertF(int fahrenhiet, int celsius, int kelvin)
{
    (celsius = (kelvin - 273));
    (fahrenhiet = (9 * celsius / 5) + 32);
     if(fahrenhiet < 33)
        {
            printf("The water is in a solid state at %d degrees fahrenhiet.\n", fahrenhiet);
        }
        else if(fahrenhiet > 32 && fahrenhiet < 212)
        {
            printf("The water is in a liquid state at %d degrees fahrenhiet.\n", fahrenhiet);
        }
        else
        {
            printf("The water is in a gas state at %d degrees fahrenhiet.\n", fahrenhiet);
        }
}
void readTemp(int kelvinNumber)
{
    int kelvin, *ptr;
    char type;
    ptr = &kelvin;
    printf("Please enter a the sample temperature in Degrees Kelvin:>345\n");
    scanf("%d", &kelvin);
    if(kelvin <= 345)
    {
        printf("You did not enter the correct value\n");
        exit(0);
    }
    else
    {
        printf("You entered %dK\n", *ptr);
    }
}


void readType(char type)
{
    int kelvin, celsius, fahrenhiet;
    printf("Do you wish to convert the temperature to (c) for Celsius, or (f) for Fahrenheit");
    getchar();
    scanf("%c", &type);
    switch(type)
    {
        case 'c' :
        celsius = convertC(kelvin, celsius);
        break;
        case 'f' :
        fahrenhiet = convertF(fahrenhiet, celsius, kelvin);
        break;
        default:
        printf("You did not enter correct letter!");
        break;
    }
}


int main()
{
   printf("Welcome to the temperature conversion program!\n");
   readTemp(kelvin);
   readType(type);
}

You need to declare the variables before you can pass them to a function.

Originally Posted by PenCzar

You need to declare the variables before you can pass them to a function.

could you give me an example please?

Originally Posted by suspense

could you give me an example please?

Code:

#include <stdio.h>

void print_int(int a);

int main(void)
{
    int x = 5;  // declare and initialize variable named "x"

    print_int(x);  // pass variable named "x" to the function

    return 0;
}

void print_int(int a)
{
    printf("%d\n", a);
}

Code:

void convert_kelvin_to_c(int kelvin) {
    int celsius = (kelvin - 273);
    printf("%d\n", celsius);
}


main() {
    convert_kelvin_to_c(500);
}

This function takes an integer, subtracts 273 from it, assigns the new value to the variable 'celsius' and then prints it out.
this program prints "227"

500 K = 226,85 NOT 227
so you must use a floating point value instead.

Code:

void convert_kelvin_to_c(float kelvin) {
    /* "%.2f" means a float with only 2 decimals trailing printed */
    float celsius = (kelvin - 273.15);
    printf("%.2f\n", celsius);
}


main() {
    convert_kelvin_to_c(500);
}

Originally Posted by Elkvis

Absolute scientific accuracy is not the point of this exercise, and is therefore off topic.

Fair enough.

Code:

#include <stdio.h>


/* add this logic */
float kelvin_to_celsius(int kelvin)
{
	printf("%d kelvin in celsius is ???\n", kelvin);
	return 0.0f;
}


/* add this logic */
float kelvin_to_fahrenheit(int kelvin)
{
	printf("%d kelvin in fahrenheit is ???\n", kelvin);
	return 0.0f;
}


int read_kelvin_temp()
{
	int kelvin;
	puts("Enter temperature in Kelvin:");
	/* if scanf() successfully scanned an integer */
	if (scanf("%d", &kelvin))
	{
		return kelvin;
	}
	/* if scanf() couldn't read format -> stdin */
	else {
		return 0;
	}
}


void read_type(int kelvin)
{
	puts("Convert to (C)elsius or (F)ahrenheit?");
	char type;
	/* if scanf() fails to find a char, set type to 'C' */
	if (!scanf(" %c", &type))
	{
		type = 'C';
	}


	switch(type)
	{
		case 'C':
		case 'c':
		{
			kelvin_to_celsius(kelvin);
			break;
		}
		case 'F':
		case 'f':
		{
			kelvin_to_fahrenheit(kelvin);
			break;
		}
		default:
		puts("Error tbh");
	}
}


int main()
{
	puts("Temperature conversion program");
	int my_kelvin = read_kelvin_temp();
	/* if the user didn't input an integer correctly */
	if (my_kelvin == 0)
	{


	}
	read_type(my_kelvin);
	return 0;
}

This is what OP wanted but he has to add logic and stuff himself.