Merge Array Issue - php

Question

I have several arrays that all have this structure:
array (
526744 =>
array (
'completed' => 13,
'total' => 24,
'topics' =>
array (
),
'lessons' =>
array (
526745 => 1,
526747 => 1,
526749 => 1,
526751 => 0,
526757 => 0,
526759 => 0,
526761 => 1,
526763 => 0,
526765 => 0,
526767 => 1,
),
'last_id' => 526793,
),
526818 =>
array (
'completed' => 0,
'total' => 22,
'topics' =>
array (
),
'lessons' =>
array (
526819 => 0,
526821 => 1,
526823 => 1,
526845 => 0,
526847 => 1,
526849 => 1,
526859 => 1,
526861 => 1,
),
'last_id' => 526861,
),
)
The number in the outer-most element of the array is a course id. The list of numbers in the inner-most array elements are lesson ids.
I want to merge all of the arrays that contain this structure together. But only ones with the course id of 526744.
If I do something like this:
foreach($results2 as $result2) {
$new_array = unserialize($result2->course_progress);
$final_array = array_merge($final_array, $new_array);
$backup_array = $new_array;
}
This works fine, but it merges the entire arrays, including all courses.
However if I specify the course_id like this:
foreach($results2 as $result2) {
$new_array = unserialize($result2->course_progress);
$newarray = $new_array[526744];
$final_array = array_merge($final_array, $new_array);
$backup_array = $new_array;
}
It no longer merges at all and just lists out the last array for that 1 single course specified.
Any ideas on what is causing this and how to fix it?
Thanks

Answer 1

I have check your code and found the issue, you have used $new_array[526744] which is wrong. it should be array($new_array[526744])
Check this code:
foreach($results2 as $result2) {
$new_array = unserialize($result2->course_progress);
$newarray = array($new_array[526744]);
$final_array = array_merge($final_array, $new_array);
$backup_array = $new_array;
}