Sort objects in array based on another array

Question

I need sort an array based on another array. Currently I have this function that creates new array containing user information.

Each user is defined in JSON string and is stored in MySQL like so:

{"Firstname":"John","Lastname":"Smith","Email":"johnsmith@outlook.com"},
{"Firstname":"Hans","Lastname":"Jobens", "Age", "Too old"}

I loop every object to get each header and then push them into headers array.

$headers = array("Age", "Email", "Firstname", "Lastname")

Then I create new user object for each user row.

$user_object = array();

And add each header to each user object and fill them with data or placeholder "-"

//add missing keys and values
foreach($users as $user){
    //get user from user row
    $row = $user['user'];
    //loop headers for each row
    foreach($headers as $header){
        //check if $header found in each row
        if (!array_key_exists($header,$row)){
            //if not found
            $row->$header = "-";
        }
    }
}

Objects are pushed into users array and now they look like this:

{"Firstname":"John","Lastname":"Smith","Email":"johnsmith@outlook.com","Age":"-"},
{"Firstname":"Hans","Lastname":"Jobens","Age":"Too old","Email":"-"}

But they are not in the right order. I want each user's object keys to maintain their values but be in order by $headers array.

Needed format:

{"Age":"-","Email":"johnsmith@outlook.com","Firstname":"John","Lastname":"Smith"},
{"Age":"Too old","Email":"-","Firstname":"Hans","Lastname":"Jobens"}

Complete code

EDIT:

Function in short:

Initialize $list, $users and $headers array
Get array of user information (stored as javascript object) from mysql
Decode and loop every user and get each object key
Append each new key into $headers array
Loop $users again to add missing keys and placeholder (dash mark)
Arrange OBJECT by $headers array
Append $headers and $users into $list
echo json_encode($list)

`Object are pushed into Users array and now they look like this` - you show a JSON string, not an array. — Alex Karshin, Dec 27 '17 at 06:53
Possibly duplicate on https://stackoverflow.com/questions/5467129/sort-javascript-object-by-key — PekosoG, Dec 27 '17 at 06:53

score 0 · Answer 1 · answered Dec 27 '17 at 07:07

0

use array_replace function

$user_object = array();
foreach($users as $user){
    // array which set order
    $template = array_fill_keys(["Age", "Email", "Firstname", "Lastname"], '-');
    // Get current existing value
    $user_object[] = array_replace($template, $user['user']);
}
print_r($user_object);

demo

answered Dec 27 '17 at 07:07

splash58

25,216
3
19
31

Not working at all. What is it even doing? I read the documentation, but it doesn't consider ordering? – Jaakko Uusitalo Dec 27 '17 at 07:30
@Jaakkouu It sets order when make template array. Then using array_replace does not change it, just replace value for the same keys – splash58 Dec 27 '17 at 07:33
@splash58 Warning: array_replace(): Argument #2 is not an array in – Jaakko Uusitalo Dec 27 '17 at 07:53
@Jaakkouu If i understood right, it should be so - https://eval.in/925838 – splash58 Dec 27 '17 at 07:59
@splash58 Not quite there. I added more information to question. Can you check it please? I am dealing with objects inside arrays. These objects need to be arranged by headers array which is dynamically build. – Jaakko Uusitalo Dec 27 '17 at 08:14

score 0 · Answer 2 · answered Dec 27 '17 at 08:57

One way is by pushing each corresponding data (-) if null as you loop thru the headers.

foreach($users as $key => $user){
    //get user from user row
    $row = $user['user'];
    // Set new row
    $newRow = [];
    // Loop thru headers
    foreach ($headers as $header) {
        // Check if row has the header, set '-' if not
        $newRow[$header] = (!array_key_exists($header, $row)) ? '-' : $row[$header];
    }
    // set key of users to newRow
    $users[$key] = $newRow;
}

print_r($users); // Print users

score 0 · Answer 3 · answered Jan 10 '18 at 10:34

0

You can order an array by key using another as a reference by combining uksort() and array_search():

uksort($array, function ($a, $b) use ($headers) {
 return array_search($a, $headers) > array_search($b, $headers);
});

answered Jan 10 '18 at 10:34

dhinchliff

1,006
8
16

uksort + array_search almost 10 times slower (php7.2) then equivalent foreach – Alexander Matrosov Jan 29 '18 at 10:30

Sort objects in array based on another array

3 Answers3