PHP I create a double variable then test it for equality and it does not match?

Asked Jan 13 '20 at 00:38

Active Jan 13 '20 at 00:39

Viewed 21 times

I can't figure out why this simple math does not work. Maybe something about PHP and numbers I am not getting?

$step=1.0;

$step+=0.1;

$substep=$step-(int)$step;

echo gettype($substep);

echo $substep;

if ($substep==0.1) { 

    echo "should be here";

} else {

    echo "but I end up here";

}

OUTPUT: double0.1but I end up here

edited Jan 13 '20 at 00:39

ChrisGPT was on strike

127,765
105
273
257

asked Jan 13 '20 at 00:38

Corbin

what exact output do you expect? – Abhishek Honrao Jan 13 '20 at 00:43
1

Because of the way floats are represented internally, two floats (double) should not be tested for equality. – Tom Kuschel Jan 13 '20 at 00:45
1

Does this answer your question? [Is floating point math broken?](https://stackoverflow.com/questions/588004/is-floating-point-math-broken) – catcon Jan 13 '20 at 00:48

PHP I create a double variable then test it for equality and it does not match?

0 Answers0