PHP JSON - have identical keys for JSON output from PHP array

Question

Is there any way to encode a PHP array (or any other similar PHP object) into JSON while having identical keys for a JSON array?

Here is an example:

{"categories" : [ {"key": "data1"}, {"key": "data2"}, {"key": "data3" } ] }

Note that the "categories" object is an array that can be simply parsed with a for loop. However, in PHP, it is impossible it seems to have identical keys in an associative array. So I can't have the structure above as my result from json_encode, and I have to have "key1", "key2", "key3", which prevents me from simply parsing it with a for loop in Javascript.

EDIT: Fixed JSON syntax EDIT2: All data is different. Keys are identical.

Answer 1

Use the php json_encode() function to turn a PHP array into a JSON string.

Reversed: json_decode()

Example:

<?php

$json = '{"categories" : { "key1": {"first":"1. value"}, "key2": "data", "key3": "data" } }';

$array = json_decode($json,true);
echo "<pre>";
print_r($array);
echo "</pre>";

Will output:

Array
(
    [categories] => Array
        (
            [key1] => Array
                (
                    [first] => 1. value
                )

            [key2] => data
            [key3] => data
        )

)

Answer 2

$array = [
    'categories' => [
        ['key' => 'data'],
        ['key' => 'data'],
        ['key' => 'data']
    ]
];

echo json_encode($array);

That's the same array structure as in your JSON. JSON has the same rules regarding unique keys as PHP does.

_{(Using PHP 5.4+ array syntax here.)}

Answer 3

Should be straightforward:

echo json_encode([
  'categories' => [
    ['key' => 'data'],
    ['key' => 'data'],
    ['key' => 'data'],
  ],
]);

Also, you can simply reverse engineer the structure by doing:

$str = '{"categories" : [ {"key": "data1"}, {"key": "data2"}, {"key": "data3" } ] }';
$arr = json_decode($str);

var_export($arr);