Change the index of an array

Question

I need help to change the index of an array.

I have this array:

$items = array('items' => array(
    0 => array(
        'item_id' => 1,
        'item_amount' => 100,
    ),
    1 => array(), 
));

Now I want to remove the index, based on the value of item_id, but I don't know how to do this.

I've tried to do it as follows, but doesn't work.

foreach($items['items'] as $key) {
  $removeIndex = $key['item_id'] == 1;
  if($removeIndex) {
     unset($removeIndex);
  }  
}

How can I do this?

do you want to just remove the `item_id` from the array if it's value is `1` ? — RomanPerekhrest, Jul 16 '16 at 16:34
You'd rather need to unset the actual array element, like `unset($key['item_id']);`. But that would as well only reset the element in the current subarray copy. — syck, Jul 16 '16 at 16:35
You are just unsetting the `$removeIndex` variable instead of the actual array item `unset($items['items'][$key])` — PeeHaa, Jul 16 '16 at 16:35
For the title: [In PHP, how do you change the key of an array element?](http://stackoverflow.com/questions/240660/in-php-how-do-you-change-the-key-of-an-array-element) — FirstOne, Jul 16 '16 at 17:06

trincot · Accepted Answer · 2016-07-16T17:31:51.383

3

You need to use unset like this:

foreach($items['items'] as $index => $key) { // also get the index!
  if (!isset($key['item_id'])) continue; // skip
  $removeIndex = $key['item_id'] == 1;
  if($removeIndex) {
     unset($items['items'][$index]['item_id']); // specify path to that entry
  }  
}

See it run on eval.in.

To unset something in your nested array structure, you need to act on that array itself. unset($removeIndex) does not change the array, because that is a boolean value.

The extra if is there for the case when you don't have an item_id in some sub-array: in that case that iteration of the loop is skipped.

Removing the entire "row"

If your aim is to also remove the sub-array to which the item_id belongs (so including the item_amount and any other value in that sub-array), then just shorten the "path" in the unset statement:

foreach($items['items'] as $index => $key) { // also get the index!
  if (!isset($key['item_id'])) continue; // skip
  $removeIndex = $key['item_id'] == 1;
  if($removeIndex) {
     unset($items['items'][$index]); // specify path to that entry
  }  
}

See it run on eval.in.

edited Jul 16 '16 at 17:31

answered Jul 16 '16 at 16:35

trincot

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Thank you so much @trincot! You helped me alot. :D. And thank for the others for the answers, I appreciate. – Amanda Thompson Jul 16 '16 at 17:00
Hey @trincot. Script unsetting all items :( – Amanda Thompson Jul 16 '16 at 17:15
Which one of the two versions are you using? – trincot Jul 16 '16 at 17:24
The second version – Amanda Thompson Jul 16 '16 at 17:31
Could you edit your question and add more data for your array, enough to see the problem? I have added some data myself on eval.in, but I don't see a problem: https://eval.in/606325 – trincot Jul 16 '16 at 17:33
Yes. The problem isn't in your code! I'll start a chat to descrbie more. – Amanda Thompson Jul 16 '16 at 17:36

syck · Answer 2 · 2016-07-16T16:48:44.133

0

If you want to remove the specific entry 'item_id' in the $items array, you have to refer to it and use both keys, like in:

foreach($items['items'] as $key => $val) {
  if (!isset($val['item_id'])) continue;
  $removeIndex = $val['item_id'] == 1;
  if($removeIndex)
     unset($items['items'][$key]);
}

If you downvote, please state why you think this answer is not appropriate.

edited Jul 16 '16 at 16:48

answered Jul 16 '16 at 16:37

syck

2,984
1
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Nope, that was intentionally, but in the end it is still unclear what the OP wants to get. It is only so hard to find that out via comments. :-) – syck Jul 16 '16 at 16:44

score 0 · Answer 3 · answered Jul 16 '16 at 16:42

You need to call unset($items['items'][0]). For your case it will be something like this:

$id = 1;
$keyToRemove = false;

foreach ($items['items'] as $key => $value) {
  if ($value['item_id'] == $id) {
    $keyToRemove = $key;
    break;
  };
}

if ($keyToRemove) {
  unset($items['items'][$keyToRemove]);
}

Change the index of an array

3 Answers3

Removing the entire "row"