Data type in C, loss of data

Question

#include <stdio.h>


int main()
{
int x;
float f1[11], f2[11], s;

for (x = 1; x <= 10; x++)
{
    f1[x] = (x * x) / 4;
    printf("f1(%d)=%.2f\n", x, f1[x]);

}

return 0;
}

f1 = (x^2)/4

Current output is:

f1(1) = 0.00

f1(2) = 1.00

f1(3) = 2.00 //etc

I kinda want those decimals though.

f1(1) = 0.25

f1(2) = 1.00

f1(3) = 2.25

@juanchopanza That's not a good duplicate, because it stores the result in an int variable. — Barmar, Oct 26 '15 at 19:58

score 1 · Answer 1 · edited Oct 26 '15 at 19:57

1

What you do with a value doesn't affect how it's computed. So the fact that you store the result of some math in a double doesn't change the fact that you're performing integer operations.

There are lots of fixes, but the simplest is probably (1.0 * x * x) / 4.0.

edited Oct 26 '15 at 19:57

Barmar

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answered Oct 26 '15 at 19:56

David Schwartz

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`x / 4. * x` is arguably simpler: fewer operations, albeit more difficult to grasp. – chqrlie Oct 26 '15 at 20:00

Data type in C, loss of data

1 Answers1