Create array with keys coming from multiple arrays

Question

I have an array that looks like this:

array(5) {
  [0]=>
  array(2) {
    ["id"]=>
    string(2) "23"
    ["my_value"]=>
    NULL
  }
  [1]=>
  array(2) {
    ["id"]=>
    string(2) "62"
    ["my_value"]=>
    NULL
  }
...

I would like to have an array that as keys have the value of the key "id" in each array and as value have the value of "my_value". However if "my_value" is NULL I want to set a value of 100.

So, the result array would be like this:

array(5) {
      [23] => 100
      [62] => 100
...

How can I do that cleanly? I have been iterating over with a foreach but I believe it can be done cleaner...

aykut · Accepted Answer · 2012-11-22 14:54:03Z

1

You can use array_map() for populate my_value

$newData = array_map(function($row) {
    if ( $row['my_value'] === null ) $row['my_value'] = 100;
    return $row;
}, $data);

But you already need a foreach loop because of formatting. So try this:

$newData = array();
foreach ($data as $row) {
    $newData[$row['id']] = ($row['my_value'] === null) ? 100 : $row['my_value'];
}

edited Nov 22, 2012 at 14:54

answered Nov 22, 2012 at 14:46

aykut

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1 Comment

Hommer Smith Over a year ago

aykut this solution won't change the indexs of the array...I want the new index to be taken from the other value in each row. Check my question, I want to change the indexs so they can take the values that are in the "id" key of each array.

pikax · Accepted Answer · 2012-11-22 15:13:11Z

1

You could do like this:

$arrayUsers = array();//declare array

$arrUser = array("id"=>"23","myvalue"=>NULL); //User 23
$arrayUsers[$arrUser["id"]] = $arrUser; //add

$arrUser = array("id"=>"62","myvalue"=>NULL); //User 62
$arrayUsers[$arrUser["id"]] = $arrUser; //add

var_dump($arrayUsers);

the result is this:

array(2) 
{ 
    [23]=> array(2) 
    { 
        ["id"]=> string(2) "23" 
        ["myvalue"]=> NULL 
    }

    [62]=> array(2) 
    { 
        ["id"]=> string(2) "62" 
        ["myvalue"]=> NULL 
    } 
}

[EDIT]

$valueArray = array();

foreach($arrayUsers as $id=>$value)
{
    $val = ($value["myvalue"]===NULL?100:$value["myvalue"]);
    $valueArray[$id] = $val;
}

var_dump($valueArray);

This should behave like you want

edited Nov 22, 2012 at 15:13

answered Nov 22, 2012 at 14:51

pikax

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Comments

dnagirl · Accepted Answer · 2012-11-22 15:00:11Z

0

$arr = array(5 => array('id'=>23, 'myvalue'=>null),
             1 => array('id'=>62, 'myvalue'=>null));

$callback = function($v) { 
  $id = $v['id'];
  $myv = !is_null($v['myvalue']) ? $v['myvalue'] : 100;
  return array($id=>$myv);

}
$newarr = array_map($callback, $arr);

answered Nov 22, 2012 at 15:00

dnagirl

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Comments

Angelo Berçacola · Accepted Answer · 2012-11-22 15:10:49Z

0

you should do it:

foreach($old_array as $value)
$new_array[$value['id']]= ($value['my_value']!==NULL) ? $value['my_value'] : 100 ;

the result will be

array(5) {
      [23] => 100
      [62] => 100
...

running code example at Codepad.org

edited Nov 22, 2012 at 15:10

answered Nov 22, 2012 at 14:48

Angelo Berçacola

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