Getting duplicate key values in array

Question

For some reason when trying to populate an array I am not getting the desired result. In the first part I create an array of arrays, the key of each has a name such as "Biology Education". But when I then populate that same array it doesn't for some reason use the same array element but a new one.

So part 1 results in an array with 13 array elements (empty). After part 2 has run the array has 26 array elements, with the first 13 empty and the other 13 populated as wanted.

The reason why I want to work is that the first 13 array elements are sorted. The last 13 are jumbled.

Why is this happening and how can I correct it?

// PART 1 
// Create array of research areas
$research_result = db_fetch_array($research['research_query_result']);
$research['areas'] = explode("\n", $research_result['options']);
// Put the values as key and every key the new value of an array object
$research['areas'] = array_fill_keys($research['areas'], array());

// PART 2 
foreach($research['user'] as $uid => &$user_object) {
    $user_object->profile_research_areas = explode(", ", $user_object->profile_research_areas);
    foreach($user_object->profile_research_areas as $key => $area) {
        $research['areas'][$area][] = $uid;
    }
}

An example of the end result is that 2 element within the array $research['areas'] looks like this:

...(26 elements)
$research['areas']['Biology Education'] (0 elements)
$research['areas']['Biology Education'] (11 elements)
...

Hope it is clear.

Can you provide a var_dump of $research['areas'] at the end of part 1, and a var dump of one of your $user_object->profile_research_areas variables? — Kevin Vaughan
– Kevin Vaughan, Commented Mar 22, 2010 at 22:02
The dump is to big but i think my last example in the main question should be enough. — JeroenEijkhof
– JeroenEijkhof, Commented Mar 22, 2010 at 22:39

Martin · Accepted Answer · 2010-03-22 22:19:04Z

1

Can't see why it would make a difference but I usually confuse my self with & and foreach loops, so try this and see it makes a difference:

// PART 2 
foreach($research['user'] as $uid => &$user_object) {
    $user_object->profile_research_areas = explode(", ", $user_object->profile_research_areas);
}

// PART 3
foreach($research['user'] as $uid => $user_object) {
    foreach($user_object->profile_research_areas as $key => $area) {
        $research['areas'][$area][] = $uid;
    }
}

answered Mar 22, 2010 at 22:19

Martin

2,9717 gold badges31 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dharman · Accepted Answer · 2024-10-15 19:03:56Z

1

You've got something like this after part 1:

$research = array(
   'areas' => array(
        'Biology education' => array(),
        'Chemistry education' => array()
   )
);

you want something like this to occur in part 2:

$research = array(
   'areas' => array(
        'Biology education' => array(42, 3.14159265, 2.181281),
        'Chemistry education' => array()
   )
);

but are ending up with:

$research = array(
   'areas' => array(
        'Biology education' => array(),
        'Biology education' => array(42, 3.14159265, 2.181281), // <--duplicate entry?
        'Chemistry education' => array()
   )
);

or am I guessing totally wrong? If that's the case, then most likely your two "Biology Education" keys are actually not the same. Perhaps one has an unprintable character embedded in it somewhere (trailing null? an   you're not seeing in a web output, etc...). Something will be causing them to be different keys, otherwise your PHP has a serious glitch in it somewhere.

edited Oct 15, 2024 at 19:03

Dharman♦

33.9k27 gold badges106 silver badges157 bronze badges

answered Mar 22, 2010 at 21:40

Marc B

362k44 gold badges433 silver badges508 bronze badges

4 Comments

JeroenEijkhof Over a year ago

So I have a key in the array called "Biology Education". And the $area variable that you pointed out has the string "Biology Education" aswell. But instead of appending the $uid variable to the existing element it creates a new one. Resulting in duplicates with keys of same names.

webbiedave Over a year ago

We need to see a dump of the array you're ending up with as well as a mocked-up dump of the array you wish you were ending up with.

JeroenEijkhof Over a year ago

I use Krumo, similar to var_dump() and print_r(). That is what has helped me understand the different outputs that I have gotten.

JeroenEijkhof Over a year ago

Sorry but that didn't work either. I'm not able to find the problem still and will simply try another approach on the key things I am trying to solve with my code. Thanks!

Collectives™ on Stack Overflow

Getting duplicate key values in array

2 Answers 2

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related