json_last_error_msg
PHP 5 >= 5.5.0, PHP 7, PHP 8
json_last_error_msg - Returns the error string of the last json_encode() or json_decode() call
Manual
json_last_error_msg(
Returns the error string of the last json_encode or json_decode call, which did not specify JSON_THROW_ON_ERROR.
Parameters
This function has no parameters.
Return Values
Returns the error message on success, or "No error" if no error has occurred.