php 二维数组怎么增加元素

$arr = ['age' => 11];
        $list = array(
            ['id'=>1,'name'=>'aaa'],

            ['id'=>2,'name'=>'bbb'],

            ['id'=>3,'name'=>'ccc']
        );
        array_walk($list, function (&$value, $key, $arr) {
            $value = array_merge($value, $arr);

        },$arr);

        var_dump($list);