Java : difference between Polymorphism and Inheritance

August 25, 2015 Leave a comment

Since the definition for both them have some common ground so it may confuse some times with the differences between this two paradigm. Definitions from wiki, you might have already read it.

  • Polymorphism : polymorphism is the provision of a single interface to entities of different types. Java supports basically subtype(using inheritance in Java) and parametric polymorphism (using generics in Java).
  • Inheritance (OOP) is when an object or class is based on another object (prototypal inheritance) or class (class-based inheritance), using the same implementation (inheriting from an object or class) specifying implementation to maintain the same behavior (realizing an interface; inheriting behavior).

So from the above definition,

  1. Inheritance or subclassing in Java is one of the technique used to achieve polymorphism.
  2. Inheritance refers to using the structure and behavior of a superclass in a subclass.
  3. Inheritance helps code reuse at the same time while achieving polymorphism.

Filed under Java, OOAD - Object Oriented Analysis and design Tagged with ,

simple C/C++ Serialization or deflating or Marshalling user defined data types or objects

September 23, 2010 1 Comment

But is it to use boost or not it is your decision 🙂  It is a good lib. But I find it very handy for small in another way as below;-

// Just a simple serialization in C++
#ifndef CVARIABLELENDATA_HPP
#define CVARIABLELENDATA_HPP

#include <string>

typedef char*	BuffPtr;
typedef size_t	BuffLen;

class CVariableLenData
{
public:
	//Serilizes data members to a char buffer
	void Serialize(BuffPtr &ptr, BuffLen len, BuffLen &writelen) const;

	//DeSerilizes from a char buffer & constructs an object
	static CVariableLenData* DeSerialize(const BuffPtr ptr, BuffLen len);

	void SetData(std::string& str);
	void SetData(int& val);

	CVariableLenData();
private:
	int m_some_int;			// fixed length
	std::string m_some_str; // variable length
	CVariableLenData(const CVariableLenData&);
};

#endif //CVARIABLELENDATA_HPP

// Source file
#include <cstdio>
#include "CVariableLenData.h"

using namespace std;

CVariableLenData::CVariableLenData():m_some_int(0),m_some_str(){}

void CVariableLenData::Serialize(BuffPtr &ptr, BuffLen bufflen, BuffLen& writelen) const
{
	if(!ptr)
		return;
	writelen = _snprintf (ptr, bufflen,"%d", m_some_int);
	*(ptr+writelen) = ' ';		// after each numeric value add an space
	size_t len = writelen + 1;
	// now write the string
	// copy length
	writelen = _snprintf ( (ptr+len), bufflen,"%u", m_some_str.length());
	*(ptr + len ) = ' ';
	len = len + writelen + 1;
	// Copy the data
	memcpy( (ptr+len), m_some_str.c_str(), m_some_str.length());
	writelen = len;
	return;
}

Some links.

Filed under C++, OOAD - Object Oriented Analysis and design, Programming