Why is it impossible to process the parsed Json?

Question

PHP

There is a url in which data is displayed in json format

spoiler

$ch = curl_init();
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('Accept: application/json'));
        curl_setopt($ch, CURLOPT_URL,$url);
        $result=curl_exec($ch);
        curl_close($ch);

json is parsed into the $result variable

spoiler

but then json_decode returns empty value
print_r(json_decode($result))
What's wrong?
ps json_last_error() produces a syntax error, but if $result is copied and pasted into the code and decoded, then
pps works fine

var_dump($result); //string(26) "{"id":1,"bc":2,"asd":3}"
        var_dump(json_decode($result)); //NULL

Answer 1

found a solution

// This will remove unwanted characters.
for ($i = 0; $i <= 31; ++$i) { 
    $result = str_replace(chr($i), "", $result); 
}
$result = str_replace(chr(127), "", $result);

// This is the most common part
// Some file begins with 'efbbbf' to mark the beginning of the file. (binary level)
// here we detect it and we remove it, basically it's the first 3 characters 
if (0 === strpos(bin2hex($result), 'efbbbf')) {
   $result = substr($result, 3);
}

$result = json_decode( $result );
print_r($result);

Answer 2

** lied
Because the result of json_decode without the second parameter is an object, not an array.
Here json_decode($res, true) will return an array

Answer 3

In any incomprehensible situation with json
json_last_error ()
json decode still does not throw errors itself, it seems like they want to fix it, but someday maybe never)