[beginner] float and division

hi this is my first post :)

Code:

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#include <stdio.h>
#include <stdlib.h>

int main() {
 
 int a,b;
 
 printf("Insert 2 numbers:\n");
 scanf("%d%d",&a,&b);

 printf("Result is: %f \n",a/b);
 
 system("pause");
 return 0;
}

---

the result isn't correct i always obtain 0.00 also if, for example, i write 8 and 2 as scanned number. why?

Try printing a and b to see that you're actually getting numbers. Also, integer division will always yield integer results.


Quzah.

cast a/b to floats with something like

(float) a / (float) b;

That provides a float result.

As it is, you're probably sending an integer when printf is expecting a float, which might easily produce nonsense.

Quote:

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Originally Posted by JVene

which might easily produce nonsense.

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Change "might" into "will" - floating point numbers are quite different from integers in their internal components. So there is no chance that a floating point number will make much sense as an integer or the other way around. It'll look as nice as monkeys typing on a calculator.

It would actually make sense to use a cast to double rather than float, since printf doesn't ever take a float argument - all floating point values will convert to double before printf gets to see the value. And you only need to cast one side of the operator, so:

Code:

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printf("%f\n", (double)a / b);

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should give the right result.

--
Mats

Ah, true - doubles....yish, I should probably stay in the C++ forum, my C is rusty.

Quote:

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Originally Posted by matsp

Change "might" into "will" - floating point numbers are quite different from integers in their internal components. So there is no chance that a floating point number will make much sense as an integer or the other way around. It'll look as nice as monkeys typing on a calculator.

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NITPICK: 0 can be represented the same way a integers and floating point. (And usually is, though sometimes -0 is used, which is equal the minimum integer value instead.)