PHP multidimensional arrays in generating question summaries

Question

The purpose of this question is to find the best way to print data out of PHP multidimensional arrays.

How can you complete the following procedure below?

I have the following arrays

array1['id']['title']

and

array2['id']['tags'][]

The arrays have been generated by the function pg_fetch_array. This allows you refer to each value of element by its name or by its key.

Procedure to get the titles for questions and their tags

I would like to do the following

1. First loop
   1. print the title from array1[$question_id]
   2. print all tags from array2[$question_id][] for the given question_id
2. Second loop
   1. do the same as in 1.1 for the next question_id in the list
   2. do the same as in 1.2 for the next question_id in the list ...
3. Continue this for all $question_ids in the list

I have used various methods unsuccessfully to complete the procedure

1. to create a multidimensional array such that I can iterate though all items in a singe -foreach: merge_unique is not enough here. Other merges also remove one column which I do not want.
2. to solve the problem with the two given arrays by while and foreach -sentences: I get 9 iterations for 3 questions as I have a foreach -clause inside a while -loop

Answer 1

Foreword: Any of the following examples should give the expected result. They just get more complicated as you go down the page, and each has its own benefits.

First, the barebones of the function. You loop through array1, and print out the title. Then you go and grab the array from array2 that has the same id as the one we are currently looking at, loop through each value, and print the value.

foreach($array1 as $id => $sub_array)
{
    echo $sub_array['title'];
    foreach($array2[$id]['tags'] as $tag)
    {
        echo $tag;
    }
}

---

Now for a little clearer one:

 // Go through each question in the first array
 // ---$sub_array contains the array with the 'title' key
 foreach($array1 as $id => $sub_array)
 {
     // Grab the title for the first array
     $title = $sub_array['title'];

     // Grab the tags for the question from the second array
     // ---$tags now contains the tag array from $array2
     $tags = $array2[$id]['tags'];

     // 1.1 Print the Title
     echo $title;

     // 1.2 Go through each tag
     foreach($tags as $tag)
     {
         echo $tag;
     }
 }

It does a few more things than it needs to, but the added steps make it more clear.

---

And Just because I love making things more complicated, you could better seperate everything by letting functions handle Title/Tag Creation, and it would create less clutter in your foreach loop, which also means less frustration.

// Go through each question in the first array
foreach($array1 as $id => $sub_array)
{
    // Grab the title for the first array
    $title = $sub_array['title'];

    // Grab the tags for the question from the second array
    $tags = $array2[$id]['tags'];

    // 1.1 Print the Title & 1.2 Print the Tags
    create_question($title, $tags);
}

// Functions

// Create all the parts of a question.
function create_question($title, $tags)
{
    create_title($title);
    create_tags($tags);
}

// Print the Title
function create_title($title)
{
    echo $title;
}

// Loop Through Each Tag and Print it
function create_tags($tags)
{
    echo "<ul>";
    foreach($tags as $tag)
    {
        echo "<li>".$tag."</li>";
    }
    echo "</ul>";
}

Answer 2

I'm sure I am missing somethnig here, but...

foreach($array1 as $id => $title) {
  echo $title['title'];
  foreach($array2[$id]['tags'] as $tag) {
    echo $tag;
  }
}