Thread: make function?

Hello everybody, I am reading a book, and there is a part that tells you how to make functions. I can only make super simple arithmetic ones, like one that will add or subtract two parameters. But ive been trying to make one where there is only one parameter, and a getchar is supposed to be converted from farenheit to celcius. It doesnt work, as when ran, and 32 is input, it comes up with 10, where it should come out with 0. What is wrong with the code?

Code:

#include <stdio.h>

int degree(int m);

/* print Fahrenheit-Celsius table
	for fahr = 0, 20, ..., 300 */
main(){
	int c;
	c = getchar();
	printf("%d", degree(c));
 	}

	int degree( int base)
	{
		int  p;
		
		p = 5 * (base-32) /9;
		return p;
}

Christ almighty... I am not at my computer, thus I have no compiler ergo I rewrote your code in JavaScript and had no troubles... Then I saw your problem.

Code:

#include <stdio.h>

int degree(int m);

/* print Fahrenheit-Celsius table
	for fahr = 0, 20, ..., 300 */
int main(void){
	int c;
	c = getchar();
	printf("&#37;d", degree(c));
                return 0;
 }

int degree( int base)
{
	int  p;

	p = 5 * (base-32) /9;
	return p;
}

Try using scanf("%d", &c) instead.

I know that there are other ways to do it, but i mean, why doesnt it work when i creat a function?

Look at the red bolded line, bud. Its not your function that is the problem, it was how you were reading input.

Example:

Code:

#include <stdio.h>

int degree(int m);

/* print Fahrenheit-Celsius table
    for fahr = 0, 20, ..., 300 */

int main(void){
    int c;

    // c = getchar();
    /* Why does this not work? Because lets say you input the number 5.
     * "5" has an ascii value of 53. So c will hold the value 53 instead of 5.
     */

    scanf("&#37;d", &c);
    /* Why does this one work? Because if you type in "535" it will retain the value
     * 535, not the character value in the input buffer.
     */

    printf("%d", degree(c));
    return 0;
 }

int degree( int base)
{
    int  p;
    p = 5 * (base-32) /9;
    return p;
}

Your function was fine. Its how you were accepting your input text that was erroneous.

51, but we still love you tabstop.

Ok, thanks. Well the point of my project is making functions, anybody got any good ideas for one for me to practice on?

Originally Posted by D3V1LD0G

Ok, thanks. Well the point of my project is making functions, anybody got any good ideas for one for me to practice on?

Pick your favorite library function from string.h and try to implement it. (No fair calling the real library function, of course.)

I think a beneficial side-lesson you should have learned during your experience with this program is not only that you can make functions, but its important to know how to use functions written by others (i.e. the C standard library function, getchar()). You should also try to use your debugger when things don't look right. Or if you are doing something small like this, you could even go ahead and put printf's all over the place. But depending on your IDE, the debugger should be the easiest to implement.