How Can Passing by Reference
When you pass data to a function, what's really passed is a copy of that data.
So, for example, if you pass a variable, a copy is made of that variable, and
that copy is actually passed to the function.
<title>Passing Reference to Functions </title>
<h1>Passing Reference to Functions </h1>
$value = 4;
echo "Before the call, \$value holds $value <br>";
echo "After the call, \$value holds $value <br>";
function squarer (&$number)
$number *= $number;