json string validation?

Question

PHP

You need to check if the incoming element is a json string.

public static function isJson($string)
    {
        json_decode($string);
        if (json_last_error() === JSON_ERROR_NONE) {
            return true;
        }
        return false;
// или
       json_decode($string);
        return (json_last_error() == JSON_ERROR_NONE);
    }
// и еще так пробовал
json_decode(123) // будет true

For digits, they return true, so how then is it safe and secure to validate the json string validation?

Answer 1

when will you learn to read the documentation?
open php.net/manual/ru/function.json-decode.php and see

Note:
PHP implements a superset of JSON, which is described in the original » RFC 7159.

follow the link to the rfc and read

JSON can represent four primitive types (strings, numbers, booleans, and null)
and two structured types (objects and arrays) .

Well, what are you going to validate if, according to the implemented standard, a number/string is a valid json?
if you really want to check that an array / object is coming in json, then use something like ideone.com/DpA6eE

Answer 2

There are a lot of correct solutions here https://stackoverflow.com/questions/6041741/fastes...