Krdytkyu

I've got a .csv file with ZIP codes containing the city and its sub-districts

67401,City 1,district_a

67401,City 2,district_b

67401,City 3,district_c

67401,City 3,district_d

67401,City 3,district_e

67401,City 3,district_f

67401,City 3,district_g

67401,City 3,district_h

67401,City 3,district_i

67401,City 3,district_j

67401,City 3,district_k

67401,City 3,district_l

67401,City 3,district_m

67401,City 3,district_n

67401,City 3,district_o

67401,City 3,district_p

67401,City 3,district_q

67401,City 3,district_r

67401,City 3,district_s

67401,City 4,district_t

67401,City 5,district_u



67501,City 6,district_v

67501,City 7,district_w

67501,City 8,district_x

67501,City 8,district_y

67501,City 8,district_z

And I need to put it in an array, where I can select/serach by the zipcode (67401, 67501, etc.) and return these results as an associative array in this format, so I can populate a select control.

For example I want to look-up all the Cities and its distrcits with zipcode 67401 I need this result:

"City 1" => [

    district_a => district_a

],

"City 2" => [

    district_b => district_b

],

"City 3" => [

    district_c => district_c

    district_d => district_d

    district_e => district_e

    district_f => district_f

    district_g => district_g

    district_h => district_h

    district_i => district_i

    district_j => district_j

    district_k => district_k

    district_l => district_l

    district_m => district_m

    district_n => district_n

    district_o => district_o

    district_p => district_p

    district_q => district_q

    district_r => district_r

    district_s => district_s

],

"City 4" => [

    district_t => district_t

],

"City 5" = [

    district_u => district_u

]

Right now I've got this working code, but I'm sure there has to be a more simple way how to achieve it.

<?php 

$zipcode = '67401';



$a = file("zip.csv", FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

$a = array_map(function ($i) {return explode(',', $i); }, $a);

$a = array_filter($a, function ($i) use ($zipcode) { return $i[0] == $zipcode; });



$b = ;

$i = 0;

foreach ($a as $key => $value) {

    $b[$i++] = [

        'city' => $value[1],

        'district'  => $value[2],

    ];

}



$c = ;



foreach($b as $key => $item) {

   $c[$item['city']][$key] = $item;

}



ksort($c, SORT_REGULAR);



$d = ;

foreach($c as $key => $value) {

    $subarray = ;

    foreach($value as $s_key => $s_val) {

        foreach($s_val as $ss_key => $ss_val) {

            $subarray[$ss_val] = $ss_val;

        }

    }

    $d[$key] = $subarray;

}



$myresult = $d;

?>

Well, first of all this data must be stored in a database, not a file. Using PDO you'll get your array in a few lines (assuming a database connection is already established):

$sql = "SELECT city, district FROM zip WHERE zipcode=? ORDER BY city, district";

$stmt = $pdo->prepare($sql);

$stmt->execute([$zipcode]);

$data = $stmt->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_COLUMN); 

As of the code present, there are way too much loops to my taste. I believe everything could be done in one loop, like

$data = ;

foreach (file("zip.csv", FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $row) {

    list($zip, $city, $district) = explode(",",$row);

    if (!isset($data[$zip])) {

        $data[$zip] = ;

    }

    if (!isset($data[$zip][$city])) {

        $data[$zip][$city] = ;

    }

    $data[$zip][$city] = $district;

}

well if you need to sort your arrays, a couple extra loops are still needed

foreach ($data as $zip => $city) {

    ksort($data[$zip]);

    foreach ($data[$zip] as $city) {

        sort($data[$zip][$city]);

    }

}

Some extra inspirational stuff ;)

// Load your CSV into array

$zipcode = '67401';

$options = ;

$fh = fopen('zip.csv', 'r');

while (($data = fgetcsv($fh)) !== false) {

    if ($zipcode == $data[0]) {

        list($zip, $city, $district) = $data;

        $options[$city][$district] = $district;

    }

}

fclose($fh);



// Sort cities

ksort($options);



// Sort districts

array_walk($options, function(&$districts) {

    ksort($districts);

});



// Enjoy!

print_r($options);