How to Intialize the Array elements value to NULL?

Usually we initialize the dynamically allocated array values to NULL using the memset.

We can do it while we allocate memory itself, by adding parenthesis ()  after the size.

Sample Code snippet:
 
int* nIntializedArray=new int[3]();

Example:

#include "stdafx.h"
#include <iostream>
#include <string>
#include <conio.h>
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
    int i=0;
    cout<<"Uninitialazied Arrary of int* \r\n\r\n";

    int* nUnIntializedArrayptr=new int[3];
    for( i=0; i<3; i++)
    {
        cout<<nUnIntializedArrayptr[i]<<"\r\n";
        
    }
    delete[] nUnIntializedArrayptr;
    cout<<"\r\n\r\n";


    cout<<"Initialazied Arrary of int* \r\n\r\n";
    int* nIntializedArray=new int[3]();
    for( i=0; i<3; i++)
    {
        cout<<nIntializedArray[i]<<"\r\n";
        
    }
    delete[] nIntializedArray;


    cout<<"UnInitialazied char* \r\n\r\n";
    char* sztxt=new char[3];
    cout<<sztxt<<"\r\n";    
    delete[] sztxt;

    cout<<"Initialazied char* \r\n\r\n";
    char* szIntialTxt=new char[3]();
    cout<<szIntialTxt<<"\r\n";    
    delete[] szIntialTxt;


    getch();
    return 0;
}

How to find the size of a dynamically allocated array?

Usually when we pass a pointer to an array to another function, we pass its size also as the parameter.
Which is not required, if the array is dynamically allocated.

We can find the size of a dynamically allocated array using _msize() function.

    TCHAR *szTxt=new TCHAR[256];
    int nArraySize=0;
    nArraySize=    _msize(szTxt)/sizeof(TCHAR);

Example:

#include "stdafx.h"
#include <iostream>
#include <conio.h>
using namespace std;

void GetIntPtrArray(int* ptrInt)
{
    //To find size of Array
    int nSize=_msize(ptrInt)/sizeof(int);
    cout<<"\r\nThe size of the Integer Array is "<<nSize;
}

void GetCharPtrArray(char* ptrchr)
{
    //To find size of Array
    int nSize=_msize(ptrchr)/sizeof(char);
    cout<<"\r\nThe size of the Char Array is "<<nSize;
}
int _tmain(int argc, _TCHAR* argv[])
{
    int *nArr=new int[10];
    GetIntPtrArray(nArr);

    char *szTxt=new char[256];
    GetCharPtrArray(szTxt);

    getch();
    return 0;
}

How to update the icon changes when installing?

BMP files can be opened using MS Paint or Windows photo viewer, or with some other programs.
But Icon of that file, is the default program that associated with that extension. you can also change the default program to open files.

Even you can create your own file extension documents for your application. To update the icon of the files and to refresh the windows after default program changed or your application installation can be done using the following code.

SHChangeNotify(SHCNE_ASSOCCHANGED,0,NULL,NULL);

How to check whether internet connection is available?

Some times we need to check the internet connection before doing updates or online license check.

How to find  it? Use the following code.

#include "intshcut.h"
#pragma comment(lib,"url.lib")

if( !InetIsOffline( 0 ))
{
    // Internet Connection is available  
}