Using the C++ class constructor and the overridden values code example


Compiler: Visual C++ Express Edition 2005

Compiled on Platform: Windows XP Pro SP2

Header file: Standard

Additional library: none/default

Additional project setting: Set project to be compiled as C++

Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C++ Code (/TP)

Other info: none

To do: Using the class constructor and the overridden values in C++ programming

To show: How to use the default and overridden constructor values of the C++ class object in C++ programming




// the C++ class constructor and destructor

#include <iostream>

using namespace std;


// class declaration

class TestConsDest


// member variable


int TestVar;

// member functions/methods, constructor, destructor and other methods


// constructor


// method

int DisplayValue();

// destructor




// class implementation

// constructor



// test how the constructor was invoked, static-retain the previous value

static int x=1;

cout<<"In Constructor, pass #"<<x<<endl;




// simple function returning a value

int TestConsDest::DisplayValue()


cout<<"I'm in DisplayValue() lor!"<<endl;

return TestVar = 100;



// destructor, clean up your work



// test how destructor was invoked

static int y=1;

cout<<"In Destructor, pass #"<<y<<endl;


// explicitly, assign a value

TestVar = 0;



// the main

int main()


// instantiate two objects. constructor should be invoked with proper memory allocation

TestConsDest Obj1, Obj2;


cout<<"\nI'm in main()...alalalalala....\n"<<endl;

cout<<"\nRe-confirm the allocation for Obj2 = "<<&Obj2<<endl;

cout<<"Default constructor value assigned = "<<Obj1.DisplayValue()<<endl;

cout<<"In main(), testing..."<<endl;

cout<<"What about Obj1 allocation? = "<<&Obj1<<endl;

cout<<"Default constructor value assigned = "<<Obj1.DisplayValue()<<endl<<endl;


return 0;



Output example:


In Constructor, pass #1

In Constructor, pass #2

I'm in main()...alalalalala....


Re-confirm the allocation for Obj2 = 0012FF48

I'm in DisplayValue() lor!

Default constructor value assigned = 100

In main(), testing...

What about Obj1 allocation? = 0012FF54

I'm in DisplayValue() lor!

Default constructor value assigned = 100

In Destructor, pass #1

In Destructor, pass #2

Press any key to continue . . .



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