https://stackoverflow.com/questions/18408640/php-warning-division-by-zero
If the expected value can be 0 (therefore does not need validation), I do this to keep things quick, clean and easy: ==>깜금한 처리
$percentage = $sum1 / ($sum2 ?: 1)
https://stackoverflow.com/questions/18408640/php-warning-division-by-zero
If the expected value can be 0 (therefore does not need validation), I do this to keep things quick, clean and easy: ==>깜금한 처리
$percentage = $sum1 / ($sum2 ?: 1)