Convenience function that retrieves the string value stored in member_name of object.
If member_name does not exist, does not contain a scalar value, or contains null, then default_value is returned instead.
the name of the object member
the value to return if member_name is not valid
the string value of the object's member, or the given default
Convenience function that retrieves the string value stored in member_name of object.
If member_name does not exist, does not contain a scalar value, or contains null, then default_value is returned instead.