PHP。 round（）工作很奇怪

Question

Here is the code:

$val = 65.5401000000000001;
return round($val ,2);

I'm expecting to get 65.54, but getting 65.54000000000001. Why it works this way? And how to get an expected value?

Answer 1

The value of the precision setting in your PHP.ini file is too high. It's best to keep it at the default 15 to prevent this happening. Basically what you're seeing is the consequence of floating point numbers not being able to handle real numbers exactly.