Answer by user2738336 for if statement with OR in php

if(($monthsDue!=1) && ($Payment_Type!=STANDING_ORDER)){    // send emails according to more criteria}

&& = AND, whereas || = OR.

http://php.net/manual/en/language.operators.logical.php

However, if you use AND and OR, you'll eventually get tripped up by something like this:

$this = true;$that = false;$truthiness = $this and $that;

Want to guess what $truthiness equals?

If you said false... wrong!

$truthiness above has the value true. Why? = has a higher precedence than and. The addition of parentheses to show the implicit order makes this clearer:

($truthiness = $this) and $that

If you used && instead of and in the first code example, it would work as expected and be false.

Just something to be careful about!