Question

I was wondering if it would be possible to do this:

$var = '$something == $somethingelse';

if ($var) { // Say hello }

and have it mean the same thing as this:

if ($something == $somethingelse) { // Say hello }

I know this will not work at the moment, because if ($var) checks to see if $var is set or not. But what I’m asking is: is there a method to allow this? Would appreciate an answer.

EDIT:
Basically I feel I should explain why I am doing this.
I want users to be able to control when they get a notification, based off some data that one of their “channels” has saved.

For instance, a user only wants to get a notification when their collected data is bigger than 60. So I would get them to choose two fields:

First field input of their number (int or float)

Second field choises (equals, <, >, =<, =>)

The last thing in this if statement would be their data collected by their “channel”.

I then want to be able to save their choice in a database, somehow, and then later act upon their choices.

Answer 1

You say this string is being generated by you elsewhere. I suggest, instead of generating a string, generate an array.

Like this: array('something','==','somethingelse').

Now when you want to process this, you can replace the variables with their values, and then check the operator and run the correct operation.

Something like this:

$x = array('something','==','somethingelse');
list($valA, $operation, $valB) = $x;

// Replace values
$valA = $$valA;
$valB = $$valB;

// Run operation
$result = false;
switch($operation){
    case '==':
        $result = $valA == $valB;
        break;
    default:
        break;
}
if($result) echo ":-)";

DEMO: http://codepad.org/vaELABEm

You can even use this to do other things, by adding more cases to the switch.