php - 数组array_merge合并 array_unique去重,implode输出自定义字符串

<?php


$a = array('123','441231','940');
$goodspdata =array (
    0 =>
        array (
            'id' => '939',
            'productsn' => '123123123',
        ),
    1 =>
        array (
            'id' => '940',
            'productsn' => '123123123',
        ),
);

foreach ($goodspdata as $gkey=>$val){

    $goodspdata[$gkey] = $val['id'];

    //array_push($a,'444');

}
$c = array_merge($goodspdata,$a);//数组合并

$b = array_unique($c);//去重
$d = implode(',',$b);//按照方式输出字符串 ps explode() ,json_encode ["940","950"]
print_r($d);