However, it, like other fundamental classes, is not defined in Objective-C itself. It is part of the Foundation framework, which offers nearly all the core utility classes you use on a day-to-day basis.Foundation provides over a dozen kinds of object families and hundreds of object classes...
When your object is returned, individual type information is not included. Instead, as shown in Figure 10.3, the objects are typed to their variable names. In this example, the return type is Person and contains types Name and ID. Figure 10.3 Returning an object of type Person. Returning an...
///Initializes all the counters for the evaluation and also takes a///cost matrix as parameter.///UseuseNoPriors()if the dataset is the test set and you///can't initialize with the priors from the training set via///setPriors(Instances).//////set of training instances, to get some...
The type defined by this declaration is actually a class. The class has exactly four instances—it is not possible to construct new objects. Therefore, you never need to use equals for values of enumerated types. Simply use == to compare them. You can, if you like, add constructors, met...
The only time to seriously consider using private attributes is when you’re worried about naming conflicts with subclasses. This problem occurs when a child class unwittingly defines an attribute that was already defined by its parent class:
Nested classes are rare. They should not be defined if they are likely to be referenced outside the containing type. Furthermore, treatpublicnested classes with suspicion; they indicate potentially poor code that is likely to be confusing and hard to discover. ...
Otherwise, it is a good idea to leave the throws specifier in place. That gives subclasses the option of throwing a CloneNotSupportedException if they can’t support cloning.You have to be careful about cloning of subclasses. For example, once you have defined the clone method for the ...
The names of proxy classes are not defined. The Proxy class in the Java 2 SDK generates class names that begin with the string $Proxy. There is only one proxy class for a particular class loader and ordered set of interfaces. That is, if you call the newProxyInstance method twice with...
An inner class is a class that is defined inside another class. Why would you want to do that? There are two reasons:Inner classes can be hidden from other classes in the same package. Inner class methods can access the data from the scope in which they are defined—including the data ...
The pointer is 4 bytes in size. So sizeof(myCar) returns 4. The object consists of two 4-byte pointers, one integer, plus one additional field that does not derive from the Car class.That extra field is from the NSObject class. Notice NSObject at the right of the colon next to ...