$a = -1; $b = 5; $c = 1.2; $d = -3.4; print abs($a)."<br />"; print abs($b)."<br />"; print abs($c)."<br />"; print abs($d)."<br />";
1
5
1.2
3.4
$a = 1.4; $b = -3.5; print ceil($a)."<br />"; print ceil($b)."<br />";
2
-3
$a = 1.4; $b = -3.5; print floor($a)."<br />"; print floor($b)."<br />";
1
-4
round(浮動点整数 , [小数点以下の桁数])
$a = 1.46; $b = -3.543212345; print round($a)."<br />"; print round($b,3)."<br />";
1
-3.543