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.)

• Alvaro Maceda: I didn't have the courage to use foreach: iteration throught arrays seems to be tricky, and I wanted to be sure that the processing order was the same.
• KIKO Software: It will most likely work, foreach simply starts with the first element, and then the next, just like your for loop.

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!

• Alvaro Maceda: But what if we have more than two levels? I wouldn't work...
• RomanPerekhrest: @AlvaroMaceda so, you should know how deep can be your config path
• Alvaro Maceda: Let's say I have ten levels.
• RomanPerekhrest: @AlvaroMaceda, ten levels? That's bad practice to construct a tangled/confused structure for intensively used config within application