Confused about accessing values in an array

Question

I'm trying to pull out the values from an array with embedded objects and I can't figure out how to reference the items I need. I call a function (working in WordPress with LearnDash plugins) which returns an array. The call I use and the echo to see the structure is:

$my_lessons = learndash_get_course_lessons_list( $course_id, $user_id,  $query_args );
    echo "<pre>";
    var_dump($my_lessons);
    echo "</pre>";

It returns:

array(10) {
  [1]=>
  array(9) {
    ["sno"]=>
    int(1)
    ["id"]=>
    int(38155)
    ["post"]=>
    object(WP_Post)#9918 (24) {
      ["ID"]=>
      int(38155)
      ["post_author"]=>
      string(1) "9"
      ["post_date"]=>
      string(19) "2023-10-07 15:01:55"
      ["post_date_gmt"]=>
      string(19) "2023-10-07 15:01:55"
      ["post_content"]=>
      string(0) ""
      ["post_title"]=>
      string(45) "Lesson 1: Happy Family, Healthy Brain (adult)"
      ["post_excerpt"]=>
      string(0) ""
      ["post_status"]=>
      string(7) "publish"
      ["comment_status"]=>
      string(6) "closed"
      ["ping_status"]=>
      string(6) "closed"
      ["post_password"]=>
      string(0) ""
      ["post_name"]=>
      string(41) "lesson-1-happy-family-healthy-brain-adult"
      ["to_ping"]=>
      string(0) ""
      ["pinged"]=>
      string(0) ""
      ["post_modified"]=>
      string(19) "2023-10-07 15:01:57"
      ["post_modified_gmt"]=>
      string(19) "2023-10-07 15:01:57"
      ["post_content_filtered"]=>
      string(0) ""
      ["post_parent"]=>
      int(0)
      ["guid"]=>
      string(68) "https://xxx.xxx.com/?post_type=sfwd-lessons&p=38155"
      ["menu_order"]=>
      int(1)
      ["post_type"]=>
      string(12) "sfwd-lessons"
      ["post_mime_type"]=>
      string(0) ""
      ["comment_count"]=>
      string(1) "0"
      ["filter"]=>
      string(3) "raw"
    }
    ["permalink"]=>
    string(121) "https://xxx.xxx.com/courses/sfp-finding-home-adult-english/lessons/lesson-1-happy-family-healthy-brain-adult/"
    ["class"]=>
    string(0) ""
    ["status"]=>
    string(9) "completed"
    ["sample"]=>
    string(13) "is_not_sample"
    ["sub_title"]=>
    string(0) ""
    ["lesson_access_from"]=>
    string(0) ""
  }

and so on for each lesson.

I want to be able to pull out the id (which is 38155) and the post_title from the object (Lesson 1: Happy Family, Healthy Brain (adult)) but I am confused on how to proceed. Any suggestions?

I tried looping though the array using

foreach ($my_lessons as $k => $v) {
    $my_return .= "<br>".$k."<br>"; 
    $my_return .= "<br>lesson: ".$v["id"]."<br>"; 
    }

This gets me the ids, but then I am not sure how to get the post_title.

Answer 1

The array returned by learndash_get_course_lessons_list() includes an object, namely an instance of the Wordpress WP_Post object. You therefore have to use a combination of array and object syntax to access the variable you want.

The WP_Post object is in the ['post'] field of each row in your array. In this case $my_lessons[0]['post']->ID and $my_lessons[0]['post']->post_title are the full names of variables you need (without using a foreach loop).

You could output the ID and name something like this:

$my_return = '';
foreach ($my_lessons as $k => $v) {
    $my_return .= "<br>Lesson name: " . $v["post"]->post_title . "<br>"; 
    $my_return .= "<br>Lesson id: " . $v["post"]->ID. "<br>"; 
}
echo $my_return;