PHP - 为什么我从编码的 object 数组中得到奇怪的结果？

Question

I have an object array in PHP, how can I echo this as JSON? I tried the json_encode but I am getting very strange results. The JSON is not between {} but between [] and it adds a 0 at the end of the output. What am I doing wrong? It makes me get an Unexpected number in JSON error in the console.

PHP

function do_get_children_as_hierarchy()
{

    if (!isset($_GET) || !isset($_GET['taxonomy_name'])) {
        echo "Parameter is missing.";
        die;
    }

    $taxonomy = $_GET['taxonomy_name'];

    $terms = get_terms(array(
        'taxonomy' => $taxonomy,
    ));

    $termObjects = [];

    foreach ($terms as $term) {
        $depth = count(get_ancestors($term->term_id, $taxonomy));
        $obj = (object) array('term_id' => $term->term_id, 'name' => $term->name, 'depth' => $depth);
        array_push($termObjects, $obj);
    }

    echo json_encode($termObjects);
}
add_action('wp_ajax_get_children_as_hierarchy', 'do_get_children_as_hierarchy');
add_action('wp_ajax_nopriv_get_children_as_hierarchy', 'do_get_children_as_hierarchy');

JSON

[
    {"term_id":415,"name":"1 kanaals","depth":2},
    {"term_id":416,"name":"12 kanaals","depth":2},
    {"term_id":417,"name":"24 kanaals","depth":2}
]0

Javascript

function do_get_terms_as_hierarchy()
{
    return '<script>
            var data = {
                "action":"get_children_as_hierarchy",
                "taxonomy_name":"productcategorie",
            };

            $.ajax({
                url: "/wp-admin/admin-ajax.php",
                type: "GET",
                data: data,
            }).then(response => {
               console.log(JSON.parse(response));
            });
    </script>';
}
add_shortcode('get_terms_as_hierarchy','do_get_terms_as_hierarchy');

Answer 1

As suggested in the comment section, probably the best solution for the 0 is to put a die() after json_encode() in order to prevent other output in the page. Also the [] it's because the values are inside an array, not an object