<?php

class A{

    static function loadById(){

        $class_name = get_called_class();

        $model = new $class_name('a');

        return $model;

    }

}

class B extends A{

    public $name;

    public function __construct($str){

        $this->name = $str;

    }

}

echo "beginnn<Br>";

$obj = B::loadById();

echo $obj->name;

?>

function arrayChangeKey($arr,$key)

    {/*{{{*/

        $processedArr = array();

        if(is_array($arr) && !empty($arr)){

            foreach ($arr as $item)

            {

                $processedArr[$item[$key]] = $item;

            }

        }

        return $processedArr;

    }