note 69021 deleted from language.operators.arithmetic by hholzgra

Note Submitter: T Chan ---- Please note that floor($a/$b) is not the same as integer division. if the 'fractional part' of $a/$b is close to 1, then it can round up, and floor($a/$b) will be larger than it should be. The example is a bit contrived though (and printf doesn't print enough digits). <?php printf("%f\n",$a = 9007199254740991); // 9007199254740991.000000 printf("%f\n", $b = $a * 3.0); //27021597764222970.000000, the actual value stored ends in 2 while the true value ends in 3 printf("%f\n", $b/$a - 3.0); //0.000000 printf("%f\n", $b - 2*$a - $a); //-1.000000 printf("%f\n",fmod($b,$a)); //9007199254740990.000000 fmod agrees too ?> Admittedly it's a bit 'specially-crafted', but it just goes to show. I believe it does work for integers that can be exactly represented in FP. But if you're dealing with ints anyway, (a-a%b)/b has no function calls and returns an int, while floor() always returns a float.