How to get a variable name as a string in PHP?

Question

Say i have this PHP code:

$FooBar = \"a string\";

i then need a function like this:

print_var_name($FooBar);

Answer 1

I know this is old and already answered but I was actually looking for this. I am posting this answer to save people a little time refining some of the answers.

Option 1:

$data = array('$FooBar');  

$vars = [];  
$vars = preg_replace('/^\\$/', '', $data); 

$varname = key(compact($vars));  
echo $varname;

Prints:

FooBar

For whatever reason you would find yourself in a situation like this, it does actually work.

.
Option 2:

$FooBar = "a string";  

$varname = trim(array_search($FooBar, $GLOBALS), " \t.");  
echo $varname;

If $FooBar holds a unique value, it will print 'FooBar'. If $FooBar is empty or null it will print the name of the first empty or null string it finds.

It could be used as such:

if (isset($FooBar) && !is_null($FooBar) && !empty($FooBar)) {
    $FooBar = "a string";
    $varname = trim(array_search($FooBar, $GLOBALS), " \t.");
}