PHP围绕不同的结果[重复]

Hi i got some problem with rounding. For ex.:

$x = 100;
$y = 4.2030;

$result = round($x / $y, 2); 

$result will be 23.79

but now

  $result2 = round(23.79 * 4.2030, 2);

$result2 will be 99.99 , so it's incorrect. should be 100 ($result2 equal $X)

how to slove it ?

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Your round precision is two decimal places. If you are trying to get whole numbers you need to omit the precision argument:

$result2 = round(23.79 * 4.2030);

NOTE: the lower the precision argument, the more inaccurate your result will be from the actual results.

You can also use ceil() and floor() if you are looking to round in a specific direction (ceil() will round up, floor() will round down).