Question

I have a string that contains elements from array.

$str = '[some][string]';
$array = array();

How can I get the value of $array['some']['string'] using $str?

Answer 1

You can do so by using eval, don’t know if your comfortable with it:

$array['some']['string'] = 'test';    
$str = '[some][string]';    
$code = sprintf('return $array%s;', str_replace(array('[',']'), array('[\'', '\']'), $str));    
$value = eval($code);    
echo $value; # test

However eval is not always the right tool because well, it shows most often that you have a design flaw when you need to use it.

Another example if you need to write access to the array item, you can do the following:

$array['some']['string'] = 'test';
$str = '[some][string]';
$path = explode('][', substr($str, 1, -1));
$value = &$array;
foreach($path as $segment)
{
    $value = &$value[$segment];
}

echo $value;
$value = 'changed';
print_r($array);

This is actually the same principle as in Eric’s answer but referencing the variable.