Want to take advantage of Java but are forced into using some native (C/C++) code. The 100% Pure Java effort is a commendable concept, however in the real world programmers often either need to re-use their existing code or in some situations It covers most SWIG features, but certain low-level details are covered in less depth than in earlier chapters. This chapter describes SWIG's support of Java. Functional interface without proxy classes.Date marshalling using the javain typemap and associated attributes.Memory management for objects passed to the C++ layer.Memory management when returning references to member variables.Void pointers and a common Java base class.Adding an equals method to the Java classes.Adding Java downcasts to polymorphic return types.Expanding a Java object to multiple arguments.Converting Java String arrays to char **.NaN Exception - exception handling for a particular type.Handling C++ exception specifications as Java exceptions.Simpler Java enums for enums without initializers.Typemaps for both C and C++ compilation.Typemaps for mapping C/C++ types to Java types.Default typemaps for non-primitive types.Overriding new and delete to allocate from Java heap.Input and output parameters using primitive pointers and references. Method access with %javamethodmodifiers.Exception handling with %exception and %javaexception.Cross language polymorphism using directors.Single threaded applications and thread safety.The premature garbage collection prevention parameter for proxy class marshalling.Further details on the generated Java classes.Pointers, references, arrays and pass by value.Modules, packages and generated Java classes.Compilation problems and compiling with C++.That’s all about polymorphism I want to share with you today. Snake, we just pass an object of Snake into the teach() method without any modification. Extensibility: when we want to add a new kind of Animal, e.g.Flexibility: the actual object can be determined at runtime which allows the code run more flexibly.Reusability: the teach() method can be re-used for different kinds of objects as long as they are sub types of the Animal interface.It increases the reusability, flexibility and extensibility of code. Why is Polymorphism?Polymorphism is a robust feature of OOP. Thus we see the outputs: Running… (from the Dog object). And depending on the actual object type, the appropriate overriding method is called. Swimming…Here, as you can see, the teach() method can accept ‘many forms’ of Animal: Dog, Bird, Fish,… as long as they are sub types of the Animalinterface.In the teach() method, the move() method is invoked on the Animal reference. For example: Trainer trainer = new Trainer() Thus we can pass any objects which are sub types of the Animaltype. How is Polymorphism Implemented in Java?In Java, you can implement polymorphism if you have a super class (or a super interface) with two or more sub classes.Let’s understand by looking at some examples.Suppose that we have the following interface and classes: public interface Animal Notice that the teach() method accepts any kind of Animal. You will understand polymorphism quickly. 12 Rules of Overriding in Java You Should Know.What is Inheritance in Java - The WHAT, WHY and HOW.So if you absorbed my lessons about inheritance and overriding the following tutorials: In other words, the actual object to which a reference type refers, can be determined at runtime.In Java, polymorphism is based on inheritance and overriding. In OOP, polymorphism means a type can point to different object at different time. What Is Polymorphism?Polymorphism means ‘many forms’.
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