read and print an integer
#include <stdio.h>
int main()
{
int a;
printf("enter int:");
scanf("%d",&a);
printf("a=%d\n", a);
return 0;
}
#include <iostream>
using namespace std;
int main()
{
int a;
cout<<"enter int:";
cin>>a;
cout<<"a="<<a;
return 0;
variable declaration
#include <stdio.h>
int main()
{
int a;
a = 20;
printf("a=%d\n",a);
int b; //error in C
return 0;
}
#include <iostream>
using namespace std;
int main()
{
int a;
a=20;
cout<<"a="<<a;
int b; //OK in C++
return 0;
}
constants
#include <stdio.h>
int main()
{
const int a=10;
int b[a]; //error in C
return 0;
}
#include <iostream>
using namespace std;
int main()
{
const int a=10;
int b[a]; //OK in C++
return 0;
}
in C:
int main(void) ==> no input parameters
int main() ==> any no of input parameters
in C++:
int main(void) ==> any no of input parameters
int main() ==> no input parameters
function overloading
#include <stdio.h>
int add_two(int x, int y);
int add_three(int x, int y, int z);
int main()
{
int s;
s=add_three(10,20,40);
printf("s=%d\n",s);
return 0;
}
int add_two(int x, int y)
{
return x+y;
}
int add_three(int x, int y, int z)
{
return x+y+z;
}
-------------below program is error in C: same name cannot be given to 2 functions-----
#include <stdio.h>
int main()
{
int s;
s=add_three(10,20,40);
printf("s=%d\n",s);
return 0;
}
int add(int x, int y)
{
return x+y;
}
int add(int x, int y, int z)
{
return x+y+z;
}
#include <iostream>
using namespace std;
int add(int x, int y);
int add(int x, int y, int z);
int main()
{
int s;
s=add(10,20,40);
cout<<"s="<<s;
return 0;
}
int add(int x, int y)
{
return x+y;
}
int add(int x, int y, int z)
{
return x+y+z;
}
Default parameters
#include <iostream>
using namespace std;
int add(int x, int y, int z=0);
int main()
{
int s;
s=add(10,20);
cout<<"s="<<s;
return 0;
}
int add(int x, int y, int z)
{
return x+y+z;
}
//Error - default parameters should be at last
#include <iostream>
using namespace std;
int add(int x, int y=0, int z);
int main()
{
int s;
s=add(10,20);
cout<<"s="<<s;
return 0;
}
int add(int x, int y, int z)
{
return x+y+z;
}
enumerations:
#include <stdio.h>
int main()
{
enum DAYS {mon, tue, wed, thu, fri, sat, sun};
enum DAYS d;
d = 2; // OK in C, and it is equal to d = wed;
printf("d=%d\n", d);
return 0;
}
//C++
#include <iostream>
using namespace std;
int main()
{
enum DAYS {mon, tue, wed, thu, fri, sat, sun};
DAYS d; //unlike C, we do not need enum keyword to declare variables
d = 2; //Not OK in C++, we have to give only d = wed;
cout<<"d="<<d;
return 0;
}
structure:
#include <stdio.h>
struct STUDENT
{
int rno;
int class_id;
float marks;
};
int main()
{
struct STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
printf("rno=%d, class_id=%d, marks=%f\n", s.rno, s.class_id, s.marks);
return 0;
}
//C++
#include <iostream>
using namespace std;
struct STUDENT
{
int rno;
int class_id;
float marks;
};
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
cout<<"rno="<<s.rno<<", "<<"class="<<s.class_id<<", "<<"marks="<<s.marks;
return 0;
}
#include <stdio.h>
struct STUDENT
{
int rno;
int class_id;
float marks;
};
void dispay_profile(struct STUDENT s);
void increment_class_id(struct STUDENT *s);
int main()
{
struct STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
dispay_profile(s);
increment_class_id(&s);
dispay_profile(s);
return 0;
}
void dispay_profile(struct STUDENT s)
{
printf("rno=%d, class_id=%d, marks=%f\n", s.rno, s.class_id, s.marks);
}
void increment_class_id(struct STUDENT *s)
{
s->class_id++;
}
#include <iostream>
using namespace std;
struct STUDENT
{
int rno;
int class_id;
float marks;
};
void dispay_profile(struct STUDENT s);
void increment_class_id(struct STUDENT *s);
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
dispay_profile(s);
increment_class_id(&s);
dispay_profile(s);
return 0;
}
void dispay_profile(struct STUDENT s)
{
cout<<"rno="<<s.rno<<", "<<"class="<<s.class_id<<", "<<"marks="<<s.marks<<endl;
}
void increment_class_id(struct STUDENT *s)
{
s->class_id++;
}
#include <iostream>
using namespace std;
struct STUDENT
{
int rno;
int class_id;
float marks;
};
void dispay_profile(struct STUDENT s);
void increment_class_id(struct STUDENT &s);
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
dispay_profile(s);
increment_class_id(s);
dispay_profile(s);
return 0;
}
void dispay_profile(struct STUDENT s)
{
cout<<"rno="<<s.rno<<", "<<"class="<<s.class_id<<", "<<"marks="<<s.marks<<endl;
}
void increment_class_id(struct STUDENT &s)
{
s.class_id++;
}
#include <iostream>
using namespace std;
struct STUDENT
{
int rno;
int class_id;
float marks;
void dispay_profile()
{
cout<<"rno="<<rno<<", "<<"class="<<class_id<<", "<<"marks="<<marks<<endl;
}
void increment_class_id()
{
class_id++;
}
};
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
s.dispay_profile();
s.increment_class_id();
s.dispay_profile();
return 0;
}
#include <iostream>
using namespace std;
struct STUDENT
{
public:
int rno;
int class_id;
float marks;
void dispay_profile()
{
cout<<"rno="<<rno<<", "<<"class="<<class_id<<", "<<"marks="<<marks<<endl;
}
void increment_class_id()
{
class_id++;
}
};
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
s.dispay_profile();
s.increment_class_id();
s.dispay_profile();
return 0;
}
#include <iostream>
using namespace std;
class STUDENT
{
public:
int rno;
int class_id;
float marks;
void dispay_profile()
{
cout<<"rno="<<rno<<", "<<"class="<<class_id<<", "<<"marks="<<marks<<endl;
}
void increment_class_id()
{
class_id++;
}
};
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
s.dispay_profile();
s.increment_class_id();
s.dispay_profile();
return 0;
}
#include <iostream>
using namespace std;
class STUDENT
{
public:
int rno;
int class_id;
float marks;
void dispay_profile();
void increment_class_id();
};
void STUDENT::dispay_profile()
{
cout<<"rno="<<rno<<", "<<"class="<<class_id<<", "<<"marks="<<marks<<endl;
}
void STUDENT::increment_class_id()
{
class_id++;
}
int main()
{
STUDENT s;
s.rno = 1;
s.class_id = 2;
s.marks = 56.98;
s.dispay_profile();
s.increment_class_id();
s.dispay_profile();
return 0;
}