Wordpress format json in postmeta table

Question

How to format the meta_value column's json from the post_meta table in wordpress to get only the proper values.

I have the value something like:

$posttype=  Mage::helper('wordpress')->getPostType2();
$posttype = explode(',',$posttype);
echo 'Post type:';

echo '<pre>';print_r($posttype);

Output:

Array ( [0] => a:12:{s:3:"key";s:19:"field_57bdd83367bb1";s:5:"label";s:4:"Type";s:4:"name";s:4:"type";s:4:"type";s:6:"select";s:12:"instructions";s:0:"";s:8:"required";s:1:"0";s:7:"choices";a:7:{s:7:"Article";s:7:"article";s:9:"Blog Post";s:9:"blog_post";s:16:"Artists & Makers";s:16:"artistsandmakers";s:6:"Videos";s:6:"videos";s:12:"In The Press";s:12:"in_the_press";s:14:"Did You Know ?";s:12:"did_you_know";s:14:"Glossary A - Z";s:8:"glossary";}s:13:"default_value";s:39:"blog_post in_the_press did_you_know ";s:10:"allow_null";s:1:"0";s:8:"multiple";s:1:"1";s:17:"conditional_logic";a:3:{s:6:"status";s:1:"0";s:5:"rules";a:1:{i:0;a:2:{s:5:"field";s:4:"null";s:8:"operator";s:2:"==";}}s:8:"allorany";s:3:"all";}s:8:"order_no";i:0;} )

I need to get only the values like in a dropdown

Article

Blog Post

Artists & Makers

<div class="category-list">
            <?php // echo $this->__('All Types') ?>
            <select id="blogcat">
                <option><?php echo $this->__('Article Type') ?></option>
                <option value=""><?php echo $this->__('All Types..') ?></option>
                <option value="<?php echo $posttype;?>"> </option>
                <?php foreach($posttype as $value) { ?>
                        <?php $namecheck = preg_replace('/\s*/', '', strtolower($value['name']));
                        if ($value['slug'] != 'artists-and-makers'&&$namecheck != 'artistsandmakers') : ?>
                        <option value="<?php echo $value['slug'];?>"><?php echo $value['name'];?> </option>
                        <?php echo 'TRUE';?>
                    <?php endif; ?>
                <?php } ?>  
                    <option value="events"><?php echo $this->__('Events') ?></option>
            </select>
        </div>

Answer 1

Part 1 - To remove the double quotes/extra characters:

Instead of trying regular expressions, since the output is somewhat predictable, I would try the following instead of the getCapitalLetters function:

function strip_cruft( $str ) {
    $str = str_replace( '";s', '', $str );
    $str = str_replace( '"', '', $str );
    return $str;
}

Part 2 - To output a populated dropdown:

Use the above function and remember to add a value in between the opening and closing tags:

<?php foreach($posttype as $post) {
    $post = strip_cruft( $post ); ?>
    <option value="<?php echo esc_attr( $post ); ?>">
        <?php echo esc_html( $post ); ?>
    </option>
<?php } ?>

If you'd like them to be all lowercase, you can use WordPress's sanitize_title function.

Answer 2

In your original question you had text like this

a:12:{s:3:"key";s:19:"field_57bdd83367bb1";s:5:"label"

This is not JSON. This is a PHP serialized Array. This is a representation of a PHP array intended for storage in a database. It is created with the serialize() function. If you try to update_post_meta() or update_option() with an Array value in WordPress then WordPress will serialize the data first. When you use get_post_meta() or get_option() WordPress will unserialize() the data for you.

Your problem here is that you're not retrieving this data with WordPress functions. You're using Mage::helper('wordpress')->getPostType2(), which appears to be a Magento function. If you're using this data in Magento then A. This is the wrong forum, please ask in a Magento forum if you have issues in Magento and B. You need to unserialize the data yourself:

$posttype=  Mage::helper('wordpress')->getPostType2();
$posttype = unserialize($posttype);
echo 'Post type:';

echo '<pre>';print_r($posttype);

PS: I rolled back your question to the first version, because it was the only version of the question that included information that explained the problem.