Create array with keys coming from multiple arrays - php

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...

Answer 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'];
}

Answer 2

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

Answer 3

$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);

Answer 4

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