Best way to save to nsuserdefaults for custom class?

Question

If I have a custom class Person which has three variables (which are propertized and synthesized):

NSString* theName;
float* theHeight;
int theAge;

Person instances are stored in an NSArray 'Group'. There is only one Group. What is the best way of storing and loading the Group in NSUserDefaults? (bearing in mind that float and int are not legal for NSUserDefaults)

Answer 1

@Brad Smith's answer is not complete, and even is incorrect in some sense. We have to use NSKeyedArchiver and NSKeyedUnarchiver as follows:

Make your class (for example in this case Person) to conform to protocol NSCoding and implement both the methods as:

- (id)initWithCoder:(NSCoder *)decoder {
    self = [super init];
    if(self) {
        self.name = [decoder decodeObjectForKey:<key_for_property_name>];
        // as height is a pointer
        *self.height = [decoder decodeFloatForKey:<key_for_property_height>];
        self.age = [decoder decodeIntForKey:<key_for_property_age>];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:self.name forKey:<key_for_property_name>];
    //as height is a pointer
    [encoder encodeFloat:*self.height forKey:<key_for_property_height>]
    [encoder encodeInt:self.age forKey:<key_for_property_age>];
}

Using NSUserDefaults

// Write to NSUserDefaults
NSData *archivedObject = [NSKeyedArchiver archivedDataWithRootObject:<your_class_object>];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:archivedObject forKey:<key_for_archived_object>];
[defaults synchronize];

// Read from NSUserDefaults
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *archivedObject = [defaults objectForKey:<key_for_archived_object>];
<your_class> *obj = (<your_class> *)[NSKeyedUnarchiver unarchiveObjectWithData:archivedObject];