创建multiroot json文件

I want to create one json file with arrays encoded as json line by line. So it would look something like this:

{...valid json 1...}
{...valid json 2...}

But when I use simple fwirte with "/n" flag to do this, I get an unexpected EOF in the first line of the json file. Like I couldnt create jsons one by one in a file, that has a .json extension.

Whats wrong, and how can I fix it?

EDIT. Sample code that I use:

$file = fopen("output.json", "w");

$arr = ['a', 'b'];

fwrite($file, json_encode($arr), "
");

fclose($file);

according to the manual, fwrite does accept the following three arguments:

resource $handle
string $string
int $length (optional)

So you would have to do the following:

$file = fopen("output.json", "w");

$arr = ['a', 'b'];

fwrite($file, json_encode($arr) . "
");

fclose($file);

Note that the string concatenation operator is . (simply a dot)

Adding to @Atmoscreations answer:

Your output format is technically not valid JSON. If you want to store a list of values/objects, you should encapsulate everything in a JSON list:

[    
    {...valid json 1...},
    {...valid json 2...},
    ...
    {...valid json N...}
]

You can do this with your PHP objects:

$file = fopen("output.json", "w");
$arr = [
    ['a', 'b'],
    ['c', 'd'],
];
fwrite($file, json_encode($arr));
fclose($file);