Variable variable usage

Houdini

I have been looking at the manual about variable variable usage and saw a script that used a while loop and made use of a count variable as shown below

$i=0;
while($i < $products_number){
$i++;
if($$i){
$message .="$$i<br>";
}
}
print("$message");

What exactly is the $$i doing in the case of this small section of code?
The way I got the meaning of the variable variable is that the variable variable takes the value of the variable in this case $i start value "0" and uses that as its name so $$i would be $0 then $1 then $2, .... or am I completely wrong here?

Drakla

You're absolutely right, but it's a terrible example because that's going to throw out errors all over the shop. Variable variables are really brilliant and make for really neat code, but find some other tutorial as that one is diabolical.

Weedpacket

Or don't take user notes as gospel 🙂

Installer

Variable variables are useful for different tasks, but they also can sacrifice readability, maintainablity, reusablilty, and scalability, etc. Often they're a poor substitute for other methods, most often arrays. That user note referred to has so many things wrong with it that it's laughable. But concerning only the use of variable variables, here's a better way to do what the person imagines his script would do:

In the form script:

echo '<input type="checkbox" name="choices[]" value="' . $products->name . '" />' . $products->name;

In the handler script:

$message = '';
foreach ($_POST['choices'] as $value) {
    $message .= $value . '<br>';
}
echo $message;