creating valid json data in Laravel - php

Question

When a new User is created, I save the username and password (no hashed) in a json file as well as in the DB, so every time I'm appending new users to the json file:
{
"user3": "demo"
} {
"user4": "demo"
} {
"user4": "demo"
} {
"user5": "demo"
}
the code:
$data = array($request->input('username') => $request->input('password'));
$datos = json_encode($data);
File::append(storage_path('archivos/datos.json'), $data);
of course the format above isn't valid json, how could i get this
[{
"user3": "demo"
}, {
"user4": "demo"
}, {
"user4": "demo"
}, {
"user5": "demo"
}, {
"user5": "demo"
}, {
"user5": "demo"
}, {
"user7": "demo"
}, {
"user8": "demo"
}]
and read it using foreach like this:
$result = File::get(storage_path('archivos/datos.json'));
$result = json_decode($result);
foreach($result as $key=>$item){
echo $key .''. $item;
}

Answer 1

First get the string from file then you can do a str_replace all "} {" with "} , {" a json also have [ at the start and ] at the end so we add them too:
$json = "[".str_replace('} {', '},{', $fileContent)."]";
Here we have a json string in $json variable so we can convert it to array by this:
$users = json_decode($json);

Answer 2

the fastest way would be to append some data:
fopen('myfile.json', 'a');
but you want to store an array, so you have to read the content of the file, update it and save it.
$users = json_decode(file_get_content(storage_path('archivos/datos.json')));
$users[] = $newUser;
file_put_contents(storage_path('archivos/datos.json'), json_encode($users, JSON_PRETTY_PRINT);
you can also make a one-liner (ugly, but works):
file_put_contents(storage_path('archivos/datos.json'), json_encode(json_decode(file_get_content(storage_path('archivos/datos.json')))[] = $newUser, JSON_PRETTY_PRINT);