Dynamically add styles to WP TinyMCE editor

I want to add custom styles to WordPress using dynamic arrays.

My question is how can I add the two arrays to the style_formats array within the ‘my_mce_before_init_insert_formats’ function dynamically?

I’ve tried using array_merge(), and a few other dynamic array techniques but it just resets the TinyMCE editor to its default settings or breaks it completely.

function my_mce_before_init_insert_formats( $init_array ) {  

  $style_formats = array(  

  array(  
      'title' => '.translation',  
      'block' => 'blockquote',  
      'classes' => 'translation',
      'wrapper' => true,

  ),  

  //add arrays here

  );  

  $init_array['style_formats'] = json_encode( $style_formats );  

  return $init_array;  

} 


//arrays to add
array(  
    'title' => '⇠.rtl',  
    'block' => 'blockquote',  
    'classes' => 'rtl',
    'wrapper' => true,
),

array(  
    'title' => '.ltr⇢',  
    'block' => 'blockquote',  
    'classes' => 'ltr',
    'wrapper' => true,
),