Creating DLL with Visual Studio 2010 Express Edition

We can create DLL with one source file and one header file. Header file contains only the declaration of the functions exported from the DLL.

Header file: header.h is the name of the header file.
extern "C" __declspec(dllexport) returntype function1(argument);
extern "C" __declspec(dllexport) returntype function2(argument);

Source file source.cpp is the name of the source file this is the actual file containing the actual functionality of the exported functions.

#include<header.h> //include the header file containing the declaration of the exported functions in the dll
returntype function1(arguments)
{
write your code here
return statement
}

returntype function2(arguments)
{
write your code here
return
}

What is the output?

main(){int x=4,y,z;y=--x;z=x--;printf("\n %d %d %d",x,y,z);}main(){int x=4,y=3,z;z=x-- -y;printf("\n %d %d %d",x,y,z);}main(){int i;for(i=1;i<=5;printf("\n %d",i);i++;}

Decimal number to Octal number conversion using C language

#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
int n,n1,o=0,r,p=0;
printf("\n Enter the number to convert octal number");
scanf("%d",&n);
n1=n;
while(n>0)
{
r=n%8;
n=n/8;
o=o+r*pow(10,p);
p++;
}
printf("\n The octal equivalanet number of %d is %d",n1,o);
printf("\n Press any key to exit");
getch();
}

Checking for Valid Triangle using C Language

/* Checking for validity of Triangle when three sides are entered*/

#include<stdio.h>
#include<conio.h>
void main()
{
int s1,s2,s3,l,s;/*s1=side one s2=side two s3=side three l=large side s=sum*/
clrscr();
printf("\n Enter the three sides of triangle");
scanf("%d %d %d",&s1,&s2,&s3);
if(s1>s2)
{
if(s1>s3)
{
s=s2+s3;
l=s1;
}
else
{
s=s1+s2;
l=s3;
}
}
else
{
if(s2>s3)
{
s=s1+s3;
l=s2;
}
else
{
s=s1+s2;
l=s3;
}
}
if(s>l)
printf("\n The triangle is valid");
else
printf("\n The triangle is invalid");
printf("\n Press any key to exit");
getch();
}

Program to check the Position of point from the center of circle using C language

#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
int x1,y1,x2,y2,r;
float dis;
clrscr();
printf("\n Enter the radius of the circle and the center coordinates");
scanf("%d%d%d",&r,&x1,&y1);
printf("\n Enter the dsired coordinate points");
scanf("%d%d%",&x2,&y2);
dis=(x2-x1)^2+(y2-y1)^2;
if(dis==(r*r))
printf("\n Enterd coordinate point lies on the circle");
else
{
if(dis>(r*r))
printf("\n Point is outside the circle");
else
printf("\n point is inside the circle");
}
printf("\n press any key to exit");
getch();
}

Checking for Collinear coordinate points in C language

#include<stdio.h>
#include<conio.h>
#include<math.h>
main()
{
int x1,x2,x3,y1,y2,y3;
float s1,s2,s3;
printf("\n Enter the first point coordinates");
scanf("%d%d",&x1,&y1);
printf("\n Enter the second point coordinates");
scanf("%d%d",&x2,&y2);
printf("\n Enter the third point coordinates");
scanf("%d%d",&x3,&y3);
/* calculating slope between the points*/
s1=abs(x2-x1)/abs(y2-y1);
s1=abs(x3-x1)/abs(y3-y1);
s3=abs(x3-x2)/abs(y3-y2);
if((s1==s2)&&(s1==s3))
printf("\n Points entered are collinear");
else
printf("\n Points entered are not collinear");
printf("\n Press any key to exit");
getch();
}

Stair case of numbers using FOR loop in C++

#include<iostream.h>
#include<conio.h>
int main()
{
int i,j,c;
clrscr();
cout<<"Enter the lines"<<"\n";
cin>>c;
for(i=0;i<c;i++)
{
for(j=0;j<=i;j++)
{
cout<<i;
}
cout<<"\n";
}
return 0;
}

Swapping using reference variables as arguments in C++

#include<iostream.h>
#include<conio.h>
void swap(int &,int &);
int main()
{
int a,b;
clrscr();
cout<<"enter the values"<<"\n";
cin>>a>>b;
cout<<"Values of a and b before swapping"<<"\n";
cout<<"a="<<a<<"\n"<<"b="<<b;
swap(a,b);
cout<<"\n"<<"The values after exchange are"<<"\n";
cout<<"a="<<a<<"\n"<<"b="<<b;
return 0;
}
void swap(int &c,int &d)
{
int t;
t=c;
c=d;
d=t;
}

Larger value in two numbers using conditional operator in C++

#include<iostream.h>
int main()
{
int a,b,r;
cout<<"Enter two numbers to calculate bigger number \n";
cin>>a>>b;
r=a>b?a:b;
cout<<"The largest number is"<<r;
return 0;
}

Display string for desired number of times using C++

#include<iostream.h>
int main()
{
int a;
cout<<"Enter number of times to print string \n";
cin>>a;
for(int i=1;i<=a;i++)
{
cout<<"Well done \n";
}
return 0;
}

Conversion of Temperature from Fahrenheit to Celsius using C++

#include<iostream.h>
#include<conio.h>
int main()
{
float f,c;
cout<<"Enter the temparature in farhenheit";
cin>>f;
c=(f-32)*5/9.0;
cout<<"\n Temparature in centigrade is:"<<c;
return 0;
}