JSON Key Ordering is a mess

TLDR;

STAY AWAY FROM IT ! USE LIST IN JSON IF YOU WANT ORDERING

JSON Key Ordering is a mess in 4 important steps : processing - encoding - storing - decoding. So it's hard to maintain the order of keys during mentioned every steps (Platform-dependent).

EXPLAIN

Imagine you have a data about exam like this

But you want to keep the ordering of people by their submitted time. So you have a dictionary (array) variable like this

$examScores = [
    'John' => 10,
    'Alex' => 8,
    'Jimmy' => 9,
];

Let try to ITERATE over it

foreach ($examScores as $name => $score) {
    echo sprintf("\n\t- %s : %d", $name, $score);
}

// We get what we want :D
/*
	- John : 10
	- Alex : 8
	- Jimmy : 9
*/

Ok, now we try to ENCODE it to string

echo json_encode($examScores);

// We get what we want
/*
{"John":10,"Alex":8,"Jimmy":9}
*/

Now, like every application, we STORE in Database which have 2 posible cases :

• Store data in TEXT type field => You have to encode data before storing, so if your programming language decoding works fine, you're fine !
• Store data in JSON type field => You also have to encode data before storing, but it depends on Database Server behavior it can sort your keys by A-Z for performance (like MySQL 5.7, 8+)

So, storing data to JSON field in MySQL (5.7 or 8+), you will get

{"Alex": 8, "John": 10, "Jimmy": 9}

MAKE IT RIGHT !

Even it runs good today, make it right for tommorow !

Make data consistent and independent from database server or programming language. Change it to more semantic and ordered struture like this

$examScores = [
    [
        'name' => 'John',
        'score' => 10,
    ],
    [
        'name' => 'Alex',
        'score' => 8,
    ],
    [
        'name' => 'Jimmy',
        'score' => 9,
    ],
];

All demo code (PHP) is here