The expression $date of type null|integer is loosely compared to true; this is ambiguous if the integer can be zero. You might want to explicitly use !== null instead.
In PHP, under loose comparison (like ==, or !=, or switch conditions),
values of different types might be equal.
For integer values, zero is a special case, in particular the following
results might be unexpected:
0==false// true0==null// true123==false// false123==null// false// It is often better to use strict comparison0===false// false0===null// false
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
integer
values, zero is a special case, in particular the following results might be unexpected: