structs.cpp

/*
 * Structs.cpp
 *
 *  Created on: Jan 4, 2012
 *      Author: behnam
 */
#include <iostream>
using namespace std;

/*
 * In C++ the only difference between a class and a struct is that class-members
 *are private by default, while struct-members default to public. So structures
 *can have constructors, ref:
 *http://www.yolinux.com/TUTORIALS/LinuxTutorialC++Structures.html
 * */

struct DataElement {
  string SVal;
  int iVal;
  bool hasData;

  DataElement() // Example of a constructor used in a structure.
  {
    iVal = -1;
    hasData = 0;
  }
};

struct Employee {
  int nID;
  int nAge;
  float fWage;
  // structs can have function as well
  int add(int a, int b) { return a + b; }
};

int Structsmain()
// int main()
{
  //	initializer list. This allows you to initialize some or all the members
  // of a struct at declaration time.
  Employee Joe = {1, 42, 60000.0f};
  Employee sJoe;
  sJoe.nID = 14;
  sJoe.nAge = 32;
  sJoe.fWage = 24.15;
  cout << sJoe.add(12, 12) << endl;

  cout << "sum up the bytes of two integers and one float=" << sizeof(sJoe)
       << endl;

  // Example of a constructor used in a structure.
  DataElement myDataElement;
  cout << myDataElement.iVal << endl;
  cout << myDataElement.hasData << endl;

  //	example of  "->" operator, when we have pointer to struct or class, for
  // accessing member we have to use -> operator
  DataElement RealData;
  DataElement *PointerToRealData = &RealData;
  PointerToRealData->iVal = 1234;
  cout << PointerToRealData->iVal << endl;

  return 0;
}