- array_map: documentation ( source)
- print_r: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
print_r(array_map(
function($str) {
return date('Y-m-d', strtotime($str));
}, [
'last day of this month',
'Last day of this month',
'lAst Day of This Month',
]
));