Hard Coded

Hard coded data in code happens when a value is set as a literal in the code, and can’t be change through any directives or parameters.

Hard-code becomes a security problem, when the hard-coded value is a password or a hash of it. This secret is now readable in the code.

<?php

// This is hard-coded
$a = 1;

// $b has a default value, but may also be changed at execution time
function foo($b = 2) {
    echo $b;
}

 ?>

Documentation