C / C++ / MFC

#include <iostream>
#include <cstring>
using namespace std;

class st{

	char *p;
	int len;

	public:
		st(){len=0; p=0;}		//creates null string
		st(const char *s);		//creates string from arrays
		st(const st &s);		//copy constructor
		~st(){delete p;}		//destructor

		//+ operator
		friend st operator + (const st &, const st &);

		//<= operator
		friend int operator <= (const st &, const st &);
		friend void show(const st);
};

st :: st(const char *s){
	len = strlen(s);
	p = new char[len+1];
	strcpy(p, s);
	//cout<<p<<"\n\n";
}

st :: st(const st &s){
	len = s.len;
	p = new char[len+1];
	strcpy(p, s.p);
	//cout<<p;
}

//overloading + operator
st operator + (const st &s, const st &t){
	st temp;
	temp.len = s.len + t.len;
	//cout<<temp.len<<" ";
	temp.p = new char[temp.len + 1];

	//cout<<s.p<<" ";
	strcpy(temp.p, s.p);
	//cout<<t.p<<" ";
	strcat(temp.p, t.p);
	//cout<<temp.p<<"\n\n";
	return(temp);
}

//overloading <= operator
int operator <= (const st &s, const st &t){
	int m = strlen(s.p);
	int n = strlen(t.p);

	if(m <= n)	return(1);
	else return(0);
}

void show(const st s){
	cout<<s.p;
}


int main(){
	st s1 = "New ";
	st s2 = "York";
	st s3 = "Delhi";
	//st string1=s1, string2=s2, string3=s1+s3;
	st string1, string2, string3;
	string1 = s1;
	string2 = s2;
	string3 = s3+s1;


	cout<<"\nstring1  =  "; show(string1);
	cout<<"\nstring2  =  "; show(string2);
	cout<<endl;
	cout<<"\nstring3  =  "; show(string3);
	cout<<"\n\n";

	if(string1 <= string2){
		show(string1);	cout<<" smaller than ";	show(string2);
		cout<<endl;
	}else {
		show(string2);	cout<<" smaller than "; show(string2);
		cout<<endl;
	}

	return 0;
}

Quote:

st string1, string2, string3;

Quote:

st string1=s1, string2=s2, string3=s1+s3;

// DTP_console.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<iostream>
#include <Windows.h>
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
#include <comutil.h>
#include <winerror.h>

SQLCHAR* dsnName = (SQLCHAR*)"Driver={Microsoft Access Driver (*.mdb, *.accdb)};dbq=C:\Program Files\MyTrading\DTP\DTP_DB.accdb;defaultdir=C:\Program Files\MyTrading\DTP;driverid=25;fil=MS Access;filedsn=C:\Program Files\MyTrading\DTP\DTP_DB.accdb.dsn;maxbuffersize=2048;maxscanrows=8;pagetimeout=5;safetransactions=0;threads=3;uid=admin;usercommitsync=Yes";

#define db "C:\\Program Files\\MyTrading\\DTP\\DTP_DB.accdb"

using namespace std;


int main()
{
	/*Data Access Method used in this example*/
	const char* DAM = "Direct ODBC";

	HENV hEnv;
	HDBC hDbc;

	//ODBC API Return Status

	RETCODE rc;

	int iConnStrLength2Ptr;
	char szConnStrOut[256];

	
	SQLWCHAR* strSQL = (SQLWCHAR*)"SELECT Exchanges.[X Name], Exchanges.[X Full Name] FROM Exchanges;";

	SQLCHAR		chval1[128], chval2[128];
	SQLWCHAR	colName[128];
	int ret1;
	int ret2;

	//Number of rows and columns in result set

	SQLINTEGER	rowCount = 0;
	SQLSMALLINT fieldCount = 0, currentField = 0;
	HSTMT		hStmt;

	//Allocate an environment handle
	rc = SQLAllocEnv(&hEnv);
	//Allocate a connection handle
	rc = SQLAllocConnect(hEnv, &hDbc);

	//Connect to database
	rc = SQLDriverConnect(hDbc, NULL, (wchar_t*)dsnName, SQL_NTS, (wchar_t*)szConnStrOut, 255, (SQLSMALLINT*)&iConnStrLength2Ptr, SQL_DRIVER_NOPROMPT);
		
	if (SQL_SUCCEEDED(rc))
	{
		printf("%s: Successfully connected to database. Data Source Name: \n %s\n",
			DAM, szConnStrOut);

		//Prepare SQL Query
		printf("%s: SQL query:\n %s\n", DAM, strSQL);

		rc = SQLAllocStmt(hDbc, &hStmt);
		rc = SQLPrepare(hStmt, strSQL, SQL_NTS);

		//Bind result set columns to the local buffers
		rc = SQLBindCol(hStmt, 1, SQL_C_CHAR, chval1, 128, (SQLLEN*)&ret1);
		rc = SQLBindCol(hStmt, 2, SQL_C_CHAR, chval2, 128, (SQLLEN*)&ret2);

		//Execute the query and create a recordset
		rc = SQLExecute(hStmt);
		if(SQL_SUCCEEDED(rc))
		{
			printf("%s: Retrieve schema info for the given result set :\n", DAM);
			SQLNumResultCols(hStmt, &fieldCount);
			if (fieldCount > 0)
			{
				for (currentField = 1; currentField <= fieldCount; currentField++)
				{
					SQLDescribeCol(hStmt, currentField, colName, sizeof(colName), 0, 0, 0, 0, 0);
					printf(" | %s", colName);
				}
				printf("\n");
			}
			else
			{
				printf("%s: Error: Number of fields in the result set is 0.\n", DAM);
			}

			printf("%s: Fetch the actual data:\n", DAM);

			//Loop through the rows in the result set

			rc = SQLFetch(hStmt);
			while (SQL_SUCCEEDED(rc))
			{
				printf(" \ %s | %s\n", chval1, chval2);
				rc = SQLFetch(hStmt);
				rowCount++;
			};

			printf("%s: Total Row Count: %d\n", DAM, rowCount);
			rc = SQLFreeStmt(hStmt, SQL_DROP);
		}

	}
	else
	{
		printf("%s: Couldn't connect to %s.\n", DAM, dsnName);
	}

	//Disconnect and free up allocated handles
	SQLDisconnect(hDbc);
	SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
	SQLFreeHandle(SQL_HANDLE_ENV, hEnv);

	printf("%s: Cleanup. Done.\n", DAM);

    return 0;
}

#include <iostream>
using namespace std;

const int size = 3;
class vector{
    int v[size];

public:
    vector();                                                                                                //constructor num vector
    vector(int *x);                                                                                          //constructor from arr
    friend vector operator * (int a, vector b);                                                              //friend 1
    friend vector operator * (vector b, int a);                                                              //friend 2
    friend istream & operator >> (istream &, vector &);      //what is this ??
    friend ostream & operator << (ostream &, vector &);        
};

Quote:

friend istream & operator >> (istream &, vector &);

class MyClass : public CScrollView
{

    public : 
             DECLARE_MESSAGE_MAP();
             void OnButtonSelect();
             void Init();
             CButton m_button;

}

// In .cpp file

BEGIN_MESSAGE_MAP(MyClass , CScrollView)

        ON_COMMAND(ID_FILE_PRINT, OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, OnFilePrintPreview)
        ON_BN_CLICKED(1010, OnButtonSelect)

END_MESSAGE_MAP()

MyClass::Init()
{
  m_button.Create(_T("Hi"),, BS_PUSHBUTTON, CRect(0, 0, 80, 20), m_cdRadViewer, 1010);
  m_button.ShowWindow(SW_SHOW);
}

MyClass:OnButtonSelect()
{
  AfxMessageBox(_T("hi, button Clicked"));
}