How to transform a json object into a key->value array

Question

I have a json object that looks something like this (truncated for readability):

{"value":["Afghanistan","Albania","Algeria","American Samoa","Andorra","Angola","Anguilla","Antarctica","Antigua and Barbuda"
],"order":[0,1,2,3,4,5,6,7,8,9
]}

How can I, using PHP, create a key->value array that I can use in a select loop?

I know how to do the select from a PHP array, but the weird setup of this JSON has me stumped. I need to use the "value" part of the JSON object as the value and the "order" as the key.

Any pointers or ideas would be appreciated.

@Rizier123, you failed to read the question fully. Decoding the JSON is only part of the question here. — Mulan, Dec 10 '15 at 14:02

score 3 · Answer 1 · answered Dec 10 '15 at 13:01

3

you can use json_decode :

$arr = json_decode($json, true);

assuming $json is your string up here

answered Dec 10 '15 at 13:01

jiboulex

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2

this is an incomplete answer. – Mulan Dec 10 '15 at 13:10

Mulan · Accepted Answer · 2015-12-10T13:15:49.810

This should help you

// your JSON string
$json = '{"value":["Afghanistan","Albania","Algeria","American Samoa","Andorra","Angola","Anguilla","Antarctica","Antigua and Barbuda"],"order":[0,1,2,3,4,5,6,7,8,9]}';

// decode the JSON string into a usable data structure in PHP
$data = json_decode($json);

// create an empty array to store your result
$map = array();

// iterate over the $data
// map each `order` to each `value`
foreach ($data->order as $idx => $key) {
  $map[$key] = $data->value[$idx];
}

// display the result
var_dump($map);

Output

array(10) {
  [0]=>
  string(11) "Afghanistan"
  [1]=>
  string(7) "Albania"
  [2]=>
  string(7) "Algeria"
  [3]=>
  string(14) "American Samoa"
  [4]=>
  string(7) "Andorra"
  [5]=>
  string(6) "Angola"
  [6]=>
  string(8) "Anguilla"
  [7]=>
  string(10) "Antarctica"
  [8]=>
  string(19) "Antigua and Barbuda"
  [9]=>
  NULL
}

You'll note that key:9 (the 10th key) is NULL because you only have 9 values.

Marcus · Answer 3 · 2015-12-10T13:22:30.937

Try this:

$json = '{"value":["Afghanistan","Albania","Algeria","American Samoa","Andorra","Angola","Anguilla","Antarctica","Antigua", "Barbuda"],"order":[0,1,2,3,4,5,6,7,8,9]}';
// create a temp array to access the JSON-Data
$array = json_decode($json, true);
// Combine the two "parts" of the JSON-Data as keys and values of the new array
$array = array_combine($array['order'], $array['value']);

print_r($array);

Output will be:

Array
(
    [0] => Afghanistan
    [1] => Albania
    [2] => Algeria
    [3] => American Samoa
    [4] => Andorra
    [5] => Angola
    [6] => Anguilla
    [7] => Antarctica
    [8] => Antigua
    [9] => Barbuda
)

(!) My solution need the same number of Kys and Values. Your JSON is "wrong" for my solution. I corrected this ("Antigua and Barbuda" --> "Antigua", "Barbuda") Have a look at @naomik post

How to transform a json object into a key->value array

3 Answers3