How can i get multi checkboxes value in metbox wordpress

Question

I make list of check boxes by WordPress meta-box and i can not get this value in my theme.

i can get my text value with this code

<? echo get_post_meta($post->ID, $prefix . 'text', true); ?>

But if i use this code in check box it give me "Array"

This is my Full code

$prefix = 'dbt_';
$meta_box = array(
'id' => 'my-meta-box',
'title' => 'Product Information',
'page' => 'post',
'context' => 'normal',
'priority' => 'high',
'fields' => array(
array(
        'name' => 'Colors',
        'desc'  => '',
        'id'    => $prefix.'colors',
        'type'  => 'checkbox_group',
        'options' => array (
        'one' => array (
        'label' => 'Black',
        'value' => 'one'
    ),
        'two' => array (
        'label' => 'White',
        'value' => 'two'
    ),
        'three' => array (
        'label' => 'Red',
        'value' => 'three'
    ),

        'four' => array (
        'label' => 'Blue',
        'value' => 'four'
    ),

        'five' => array (
        'label' => 'Green',
        'value' => 'five'
    ),

        'six' => array (
        'label' => 'Yellow',
        'value' => 'six'
    ),

        'seven' => array (
        'label' => 'Brown',
        'value' => 'seven'
    )
)
)
)
);

  add_action('admin_menu', 'mytheme_add_box');
// Add meta box
function mytheme_add_box() {
global $meta_box;
add_meta_box($meta_box['id'], $meta_box['title'], 'mytheme_show_box', $meta_box['page'], $meta_box['context'], $meta_box['priority']);
}

    // Callback function to show fields in meta box
function mytheme_show_box() {
global $meta_box, $post;
// Use nonce for verification
echo '<input type="hidden" name="mytheme_meta_box_nonce" value="', wp_create_nonce(basename(__FILE__)), '" />';
echo '<table class="form-table">';
foreach ($meta_box['fields'] as $field) {
// get current post meta data
$meta = get_post_meta($post->ID, $field['id'], true);
echo '<tr>',
'<th style="width:20%"><label for="', $field['id'], '">', $field['name'], '</label></th>',
'<td>';
switch ($field['type']) {
case 'checkbox_group':
foreach ($field['options'] as $option) {
    echo '<input type="checkbox" value="'.$option['value'].'" name="'.$field['id'].'[]" id="'.$option['value'].'"',$meta && in_array($option['value'], $meta) ? ' checked="checked"' : '',' />
            <label for="'.$option['value'].'">'.$option['label'].'</label><br />';
}
break;
}
echo '</td><td>',
'</td></tr>';
}
echo '</table>';
}


add_action('save_post', 'mytheme_save_data');
// Save data from meta box
function mytheme_save_data($post_id) {
global $meta_box;
// verify nonce
if (!wp_verify_nonce($_POST['mytheme_meta_box_nonce'], basename(__FILE__))) {
return $post_id;
}
// check autosave
if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
return $post_id;
}
// check permissions
if ('page' == $_POST['post_type']) {
if (!current_user_can('edit_page', $post_id)) {
return $post_id;
}
} elseif (!current_user_can('edit_post', $post_id)) {
return $post_id;
}
foreach ($meta_box['fields'] as $field) {
$old = get_post_meta($post_id, $field['id'], true);
$new = $_POST[$field['id']];
if ($new && $new != $old) {
update_post_meta($post_id, $field['id'], $new);
} elseif ('' == $new && $old) {
delete_post_meta($post_id, $field['id'], $old);
}
}
}

any body Can give me the correct full code to get my values because I`m trying to learn PHP language

It`s my first WordPress theme and i hope if i can finish it fast,

Thank you

Answer 1

This typically happens when you try to cast an array as a string. For example:

$data = array('one', 'two', 'three');
echo $data;
// will echo Array

Revisit your loop and how you're accessing it's values. Use something like print_r() or var_dump() to preview the data before using it.

Answer 2

Inside your array loop maybe adding a second loop would get you the array values you need. Also, your code inside the loop at first glance looks like there could be some syntax errors

foreach ($field['options'] as $options) {
    foreach ($options as $option) {
    ...
    ...
    }
}

Not tested but here is an example

 foreach ($field['options'] as $options) {
    foreach ($options as $option) {              
        $checked = $meta && in_array($option['value'], $meta) ? 'checked="checked"' : '';
        echo '<input type="checkbox" value="' . $option["value"] . '" name="' . $field["id"] . '[]" id="' . $option["value"] . ' ' . $checked . ' />';
        echo '<label for="' . $option["value"] . '">' . $option["label"] . '</label>';
        echo '<br />'; 
    }
 }