Is there a way to get the name of a variable? PHP - Reflection

Question

I know this is not exactly reflection, but kind of. I want to make a debug function that gets a variable and prints a var_dump and the variable name.

Of course, when the programmer writes a call to the function, they already know the variable's name, so they could write something like:

debug( $myvar, 'myvar' );

But I want it to be quick and easy to write, just the function name, the variable, and voilà !

debug( $myvar ); // quicker and easier :)

Answer 1

Nope, not possible. Sorry.

Answer 2

No, the closer you will get is with get_defined_vars().

EDIT: I was wrong, after reading the user comments on get_defined_vars() it's possible with a little hack:

function ev($variable){
    foreach($GLOBALS as $key => $value){
        if($variable===$value){
            echo '<p>$'.$key.' - '.$value.'</p>';
        }
    }
}

$lol = 123;

ev($lol); // $lol - 123

Only works for unique variable contents though.

Answer 3

i've had the same thought before, but if you really think about it, you'll see why this is impossible... presumably your debug function will defined like this: function debug($someVar) { } and there's no way for it to know the original variable was called $myvar.

The absolute best you could do would be to look at something like get_defined_vars() or $_GLOBALS (if it were a global for some reason) and loop through that to find something which matches the value of your variable. This is a very hacky and not very reliable method though. Your original method is the most efficient way.

Answer 4

Not elegantly... BUT YOU COULD FAKE IT!

• 1) Drink enough to convince yourself this is a good idea (it'll take a lot)
• 2) Replace all your variables with variable variables:

$a = 10
//becomes
$a = '0a';
$$a = 10;

• 3) Reference $$a in all your code.
• 4) When you need to print the variable, print $a and strip out the leading 0.

Addendum: Only do this if you are

• Never showing this code to anyone
• Never need to change or maintain this code
• Are crazy
• Not doing this for a job
• Look, just never do this, it is a joke

Answer 5

You could use eval:

function debug($variablename)
{
  echo ($variablename . ":<br/>");
  eval("global $". $variablename . ";");
  eval("var_dump($" . $variablename . ");");
}

Usage: debug("myvar") not debug($myvar)

Answer 6

Bit late to the game here, but Mach 13 has an interesting solution: How to get a variable name as a string in PHP