One more reason to occurrence of these errors is unexpected whitespace like similar characters with-in code, the code lines seems to be perfect, but they contains some specific characters which are similar to break line or whitespace or tab but they not get parsed by the parser. I face this issue when I try to put some code from webpage to the code editor by simply copy paste, I saw this error with array definition. everything was looking right in array definition. I can't sort out right error, finally I define this array in single line, then error was gone. then again I try to make that definition multiple like but manually adding break(Enter) for each array element and saved the file this time no parsing error by editor and also no error while running it. For Example I faced issue with this snippet which was on one blog, actually can't post those snippets ,cause stack overflow already knows the problem with code.

then after solving it my working snippet is, which looks similar with one which shows parsing error

syntax error, unexpected ''auth'' (T_CONSTANT_ENCAPSED_STRING), expecting ']'

    public $aliases = [
        'csrf'=> \CodeIgniter\Filters\CSRF::class,
        'toolbar'=> \CodeIgniter\Filters\DebugToolbar::class,
        'honeypot'=> \CodeIgniter\Filters\Honeypot::class,
        'auth' => \App\Filters\Auth::class,
];