Array helper methods/functions - flatten / object2array / array2object / recursive unique

ArrayHelper.php

<?php
/**
 * Created by PhpStorm.
 * User: Kai Bartholome
 * Date: 20.12.2016
 * Time: 15:20
 */

namespace app\components;

/**
 * Class ArrayHelper 
 * @package app\components
 */
class ArrayHelper
{

    /**
     * @param $array
     * @param null $key
     * @return array
     */
    public static function unique($array,$key = null){
        if(null === $key){
            return array_unique($array);
        }
        $keys=[];
        $ret = [];
        foreach($array as $elem){
            $arrayKey = (is_array($elem))?$elem[$key]:$elem->$key;
            if(in_array($arrayKey,$keys)){
                continue;
            }
            $ret[] = $elem;
            array_push($keys,$arrayKey);
        }
        return $ret;
    }

    
    /**
     * @param $object
     * @return array
     */
    public static function stdObject2Array($object){
        return json_decode(json_encode($object), true);
    }

    /**
     * @param $object
     * @return \stdClass
     */
    public static function array2StdObject($object){
        return json_decode(json_encode($object), false);
    }

    /**
     * Flatten an array
     * @param $array
     * @return array
     * @throws \Exception
     */
    public static function flatten($array)
    {
        $returnArray=[];
        foreach($array as $key=>$value){
            if(!is_array($value) && !is_object($value)) {
                $returnArray[] = $value;
            }else if(is_array($value)){
                $returnArray = array_merge($returnArray,self::flatten($value));
            }else if(is_object($value)){
                $value = json_decode(json_encode($value), true);
                $returnArray = array_merge($returnArray,self::flatten($value));
            }else{
                throw new \Exception('Unknown value type');
            }
        }
        return $returnArray;
    }

}