将价格四舍五入到最接近的 $xx.99

Round prices to nearest $xx.99

我想将价格四舍五入(向上或向下)到最接近的 $xx.99

例如:

.99 -> Stay as is

.03 -> .99

.85 -> .99

 -> .99

加0.01,四舍五入,减0.01

$input = 17.99; // example input
$add = $input + 0.01;
$round = round($add);
$output = $round - 0.01;

或一体机:

return round($input + 0.01) - 0.01;