/**
* get the average of the items
*
* @param array[array] $arr
* @param string $key
*/
public static function average($arr, $key = null)
{
if (!is_array($arr)) {
throw new \InvalidArgumentException('CCArr::average - first argunent has to be an array.');
}
if (is_string($key) && CCArr::is_multi($arr)) {
$arr = CCArr::pick($key, $arr);
}
return static::sum($arr) / count($arr);
}
/**
* test values by key
*
* @expectedException InvalidArgumentException
*/
public function testArrayPickException()
{
CCArr::pick('test');
}