Question 1: Explain the output of the below code:
<?php $x = true and false; var_dump($x); ?>
Surprisingly to many, the above code will output bool(true) seeming to imply that the and operator is behaving instead as an or.
The issue here is that the = operator takes precedence over the and operator in order of operations, so the statement $x = true and false ends up being functionally equivalent to:
<?php $x = true; // sets $x equal to true true and false; // results in false, but has no affect on anything ?>
This is, incidentally, a great example of why using parentheses to clearly specify your intent is generally a good practice, in any language. For example, if the above statement $x = true and false were replaced with $x = (true and false) , then $x would be set to false as expected.
Question 2: What will $x be equal to after the statement $x = 3 + “15%” + “$25” ?
The correct answer is 18.