[rake]

Array do's and don'ts
Why is $foo[bar] wrong?
You should always use quotes around an associative array index. For example, use $foo['bar'] and not $foo[bar]. But why is $foo[bar] wrong? You might have seen the following syntax in old scripts:


<?php
$foo[bar] = 'enemy';
echo $foo[bar];
// etc
?>



This is wrong, but it works. Then, why is it wrong? The reason is that this code has an undefined constant (bar) rather than a string ('bar' - notice the quotes), and PHP may in future define constants which, unfortunately for your code, have the same name. It works, because the undefined constant gets converted to a string of the same name automatically for backward compatibility reasons.