How to dynamically define a variable in PHP

Question

Is there a way to name or define a variable based on the value of another variable?

I have a MySQL result set in $row[1].

I am trying to dynamically name a variable by appended the beginning of a variable with the value of $row[1] as follows:

$sampleVar.$row[1] = 'a string';

But get this error: Fatal error: Only variables can be passed by reference in...

More Info:

I have these variables predefined:

$sampleVar01 = '';
$sampleVar02 = '';
$sampleVar03 = '';
$sampleVar04 = '';

The result of $row[1] will, in fact be either "01", or "02", or "03", or "04".

Don't do it. Just use an array. You will thank me later: $sampleVar[$row[1]] = 'a string'; — AbraCadaver
– AbraCadaver, Commented May 22, 2016 at 3:56
Not sure what you mean @AbraCadaver. My illustration and question was simply to find out if I could dynamically make up a variable, which (at)LucM helped me to achieve. My script and usage is way more complex than this simple example. Each of the $sampleVar99's are, in fact, arrays in and of themselves in my script. But for the very essence of my question, (at)LucM shows how to do it. Honestly, I was too deep in it and overthinking it. A fresh set of eyes from (at)LucM helped me to actually see the solution it so obviously. I appreciated his assistance. — H. Ferrence
– H. Ferrence, Commented May 22, 2016 at 11:13

Luc M · Accepted Answer · 2016-05-22 01:44:18Z

1

What you are looking for is called variable variables

$var = $sampleVar.$row[1]
$$var = 'a string';

EDIT

After your edit, here's what you need to do:

$var = 'sampleVar' . $row[1];
$$var = 'a string';
echo $sampleVar01;

answered May 22, 2016 at 1:35

Luc M

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6 Comments

Ah, no I did not. But I will now @LucM

It did not work. I get this error Notice: Undefined variable: sampleVar in

Of course, your variables sampleVar and $row[1] must be defined.

see my "more info" in my OQ if that helps to answer my question ... "can this actually be accomplished".

Thanks for the EDIT @LucM. i'll try that now.

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