Variable Variables Pointing to Arrays or Nested Objects

Question

Is it possible to create a variable variable pointing to an array or to nested objects? The php docs specifically say you cannot point to SuperGlobals but its unclear (to me

Answer 1

Nope you can't do that. You can only do that with variable, object and function names.

Example:

 $objvar = 'classObj';
 var_dump(${$OBJVarVar}->var);

Alternatives can be via eval() or by doing pre-processing.

$arrayTest = array('value0', 'value1');
$arrayVarTest = 'arrayTest[1]';

echo eval('return $'.$arrayVarTest.';');
eval('echo $'.$arrayVarTest.';');

That is if you're very sure of what's going to be the input.

By pre-processing:

function varvar($str){
  if(strpos($str,'->') !== false){
    $parts = explode('->',$str);
    global ${$parts[0]};
    return $parts[0]->$parts[1];
  }elseif(strpos($str,'[') !== false && strpos($str,']') !== false){
    $parts = explode('[',$str);
    global ${$parts[0]};
    $parts[1] = substr($parts[1],0,strlen($parts[1])-1);
    return ${$parts[0]}[$parts[1]];
  }else{
    return false;
  }
}

$arrayTest = array('value0', 'value1');
$test = 'arrayTest[1]';
echo varvar($test);