php & json: json_decode check errors

Trabla:  php & json: json_decode check errors

Solving:

Php function json_decode in case of json parsing errors returns null.
To catch errors use function  json_last_error - returns the last error occurred ( int code )

(PHP 5 >= 5.5.0, PHP 7)

json_last_error_msg — Returns the error string of the last json_encode() or json_decode() call

Example:

$valid_json = '{"name":"Trololo"}';
$invalid_json = '{"name":"Trololo" ';

$obj = json_decode( $valid_json );

$obj = json_decode( $invalid_json );

switch (json_last_error()) {
 case JSON_ERROR_NONE: 
      echo ' - No errors'; 
      break; 
case JSON_ERROR_DEPTH: 
       echo ' - Maximum stack depth exceeded'; 
       break; 
case JSON_ERROR_STATE_MISMATCH: 
       echo ' - Underflow or the modes mismatch'; 
        break; 
case JSON_ERROR_CTRL_CHAR: 
        echo ' - Unexpected control character found'; 
        break; 
case JSON_ERROR_SYNTAX: 
        echo ' - Syntax error, malformed JSON'; 
        break; 
case JSON_ERROR_UTF8: 
        echo ' - Malformed UTF-8 characters, possibly incorrectly encoded'; 
        break; 
default: 
        echo ' - Unknown error'; 
break; 
}

Official Docs:

json_decode - http://php.net/manual/en/function.json-decode.php
json_last_error - http://php.net/manual/en/function.json-last-error.php