Unable to calculate float values

[CHurst]

Hi.

I'm very new to the C programming language. I am using "The C Programming Language (2nd Edition)" by Kernighan and Ritchie with the Apple Xcode IDE. I am trying to complete Exercise 1-4 found on page 13 modified with float values instead of int values. My code is found first below and resulting output is found below that.

#include <stdio.h>

main()
{
	float fahr, celsius;
	int lower, upper, step;
	
	lower = 0;
	upper = 300;
	step = 20;
	
	celsius = lower;
	while (celsius <= upper) {
		fahr = ((celsius * 9.0) / 5.0) + 32.0;
		printf("%6.2f\t%6.2f \n", celsius, fahr);
		celsius = celsius + step;
	}

return 0;

}

[Session started at 2005-12-08 17:14:28 -0500.]
  0.00	 32.00 
 20.00	 68.00 
 40.00	104.00 
 60.00	140.00 
 80.00	176.00 
100.00	212.00 
120.00	248.00 
140.00	284.00 
160.00	320.00 
180.00	356.00 
200.00	392.00 
220.00	428.00 
240.00	464.00 
260.00	500.00 
280.00	536.00 
300.00	572.00 

KR has exited with status 0.

As you can see, the output values are float but are rounded to int values. My Build Results console gives me one warning - "warning: return type defaults to 'int'." Can someone help me locate the source of my problem.

Thanks a lot in advance!

[SlyMaelstrom]

Because the C to F equation yields whole numbers when counting by 20.

Change step to something like 8 to see some numbers on the left side of the decimal.

...and your warning is coming from main()

int main()

[CHurst]

Thank you sir!