Question

Can I compare two dates in a string like numbers? Or should I retype them to ints?

Is this code ok?

<?php
$date1 = "20130102";
$date2 = "20151012";

if ($date1 < $date2){
    echo "date1 < date2";
} elseif ($date1 > $date2){
    echo "date1 > date2";
} else {
    echo "date1 = date2";
}
?>

Answer 1

Your code is safe and correct under the following condition: Iff your dates are formatted like Ymd (according to php’s date function)

The reason this works is that in all character sets that I can imagine the characters 0-9 sort exactly like the numbers 0-9 do. If you then use leading 0s your strings sort just like numbers.

N.B. that using strings as a data type for dates is a code smell. See this page (no.7)