<?php

//stdClass array
$sizes = [];

$size = new \stdClass();
$size->code = '1';
$size->name = 'フリー';
array_push($sizes, $size);

$size = new \stdClass();
$size->code = '2';
$size->name = 'S';
array_push($sizes, $size);

var_dump($sizes);

// stcClass to array
$size2 = [];
foreach ($sizes as $size) {
    var_dump($size);
    var_dump((array) $size);
}