Question

Is there any library function for this purpose, so I don’t do it by hand and risk ending in TDWTF?

echo ceil(31497230840470473074370324734723042.6);  // Expected result 31497230840470473074370324734723043  // Prints <garbage> 

Answer 1

This will work for you:

$x = '31497230840470473074370324734723042.9';  bcscale(100); var_dump(bcFloor($x)); var_dump(bcCeil($x)); var_dump(bcRound($x));  function bcFloor($x) {     $result = bcmul($x, '1', 0);     if ((bccomp($result, '0', 0) == -1) && bccomp($x, $result, 1))         $result = bcsub($result, 1, 0);      return $result; }  function bcCeil($x) {     $floor = bcFloor($x);     return bcadd($floor, ceil(bcsub($x, $floor)), 0); }  function bcRound($x) {     $floor = bcFloor($x);     return bcadd($floor, round(bcsub($x, $floor)), 0); } 

Basically it finds the flooy by multiplying by one with zero precision.

Then it can do ceil / round by subtracting that from the total, calling the built in functions, then adding the result back on

Edit: fixed for -ve numbers