- number_format: documentation ( source)
<?php
function roundDownToHalf($number) {
$remainder = ($number * 10) % 10;
$half = $remainder >= 5 ? 0.5 : 0;
$value = floatval(intval($number) + $half);
return number_format($value, 1, '.', '');
}
print roundDownToHalf(4.9) . "\n";
print roundDownToHalf(4.8) . "\n";
print roundDownToHalf(4.5) . "\n";
print roundDownToHalf(3.8) . "\n";
print roundDownToHalf(2.3) . "\n";
print roundDownToHalf(1.0) . "\n";
?>