How to handle data in the form of 3.5527136788005e-15 in PHP gracefully

Question

-3.5527136788005e-15
3.5527136788005e-15

php Under what circumstances will such scientific notation appear?
Is there a function that can directly approximate 0?
Have you ever encountered this?

Answer 1

$num = 3.5527136788005e-15;

var_dump(number_format($num));

One step to get it right:

$num = $num < 1 ? 0 : number_format($num, 2);
var_dump($num);

Reference: number_format

Answer 2

If the decimal point exceeds a few decimal points, it will appear and can be set. If the data is not required to be accurate, rounding can be done