php 去掉小数

$num = 3.14;
$rounded_num = floor($num);
echo $rounded_num; // 输出 3

$num = 3.14;
$rounded_num = intval($num);
echo $rounded_num; // 输出 3

$num = 3.14;
$rounded_num = (int)$num;
echo $rounded_num; // 输出 3

$num = 3.14;
$rounded_num = (string)$num;
$rounded_num = substr($rounded_num, 0, strpos($rounded_num, '.'));
echo $rounded_num; // 输出 3

$num = 123456789.123456789;
$rounded_num = bcdiv($num, 1, 0);
echo $rounded_num; // 输出 123456789

$num = -3.6;
$rounded_num = round($num);
echo $rounded_num; // 输出 -4