Access an associative array value given an array of keys in PHP

Question

I have an object which stores an app configuration in an associative array, as this:

[
  'Database' => 
    [
      'DB_SERVER' => 'localhost'
      'DB_NAME' => 'adbname'
      'DB_USER' => 'theuser'
      'DB_PASS' => 'thepass'
    ]
]

And a function, get(), which receives a variable number of arguments and returns the configuration value for this parameters. For example, Config::get('Database','DB_PASS') will return 'thepass'.

This is an excerpt of the code:

class Config
{
    protected static $values;

    ...

    public static function get()
    {
        $val = &self::$values;
        $argList = func_get_args();
        for ($i = 0; $i < count($argList); $i++) {
            $val = &$val[$argList[$i]];
            if(empty($val)) break;
        }
        return (is_null($val)?"":$val);
    }
}

Is there a more elegant / efficient way of accessing the value?

Answer 1

This seems alright, but you could use foreach, and checking and returning can be simpler:

class Config
{
    protected static $values;

    ...

    public static function get()
    {
        $val = &self::$values;
        foreach(func_get_args() as $argument)
        {  
          $val = &$val[$argument];
          if(empty($val)) return "";
        }
        return $val;
    }
}

I would call this more elegant, but it's not more efficient. (I did not test the code.)

Answer 2

There is more accurate and efficient way to access config options:

class Config {

    protected static $values = [    // exemplary config array
        'Database' =>
                [
                    'DB_SERVER' => 'localhost',
                    'DB_NAME' => 'adbname',
                    'DB_USER' => 'theuser',
                    'DB_PASS' => 'thepass'
                ],
        'testUrl' => "http://myexample.com"     // 1st level option
    ];

    public static function get() {
        $args = func_get_args();
        $count = count($args);

        if ($count == 0 || empty($args[0])) {
            throw new \Exception("Unspecified config option!");
        }
        if ($count == 1 && isset(self::$values[$args[0]])) {
            return self::$values[$args[0]];
        } elseif ($count == 2 && isset(self::$values[$args[0]])
                && is_array(self::$values[$args[0]]) 
                && isset(self::$values[$args[0]][$args[1]])) {
            return self::$values[$args[0]][$args[1]];
        }

        return null;
    }
}

print_r(Config::get('Database','DB_PASS'));  // "thepass"
print_r(Config::get('testUrl'));             // "http://myexample.com"
print_r(Config::get(""));              // will throw an exception: Unspecified config option!