文件中的Json返回null

I need to get a language file stored in a json file. The problem is that it always returns null, even when the document encoding in the file is UTF-8.

    $file = fopen("./language/english/english.json", "r");
    while(!feof($file))
    {
        $lines = fgets($file);
        $data = json_decode($lines, true);
        var_dump($data);
    }

    fclose($file);

english.json

{
    "english": {
        "hello_world": "test"
    }
}

returns

NULL NULL NULL NULL NULL

$file = "./language/english/english.json";
$data = json_decode(file_get_contents($file), true);
var_dump($data);

Problem is that you are trying to decode a line at a time (inside line reading while loop). Use file_get_contents() to get all json data and decode after that. As getting correctly formed JSON files may be tricky, I would suggest some error checking along the line too.

Something like this:

$filename = "./language/english/english.json";

if (!file_exists($filename)){
  print('No file!');
  die();
}

$data = json_decode(file_get_contents($filename), true);

// check if there was a json decode error
if (json_last_error()){
  print('JSON error: '.json_last_error_msg());
  die();
}

print('<pre>');
print_r($data);