presentation on structure,functions and classes
DESCRIPTION
TRANSCRIPT
Arrays can be used to represent a group of data items that belong to the same type, such as int or float .
If we want to represent a collection of data items of different types using a single name then we cannot use an array.
The data type which we use is known as structure. Structure is user defined data type.
struct struct_name
{
data_type member1;
data_type member2;
… …
};
//header files
#include<stdio.h>
#include<conio.h>
//Structure declaration
struct student
{
// data types & members
int rollno;
char name[20];
};
void main ()
{
struct student S1; //Structure variable
printf(“Input the name of student “);
scanf(“%d”,&S1.name);
printf(“Input the Roll number of student “);
scanf(“%d”,&S1.rollno);
printf(“name =%d“S1.name);
printf(“Roll number=%d“S1.rollno);
getch();
}
Input the name of student abc
Input the Roll number of student 1
name = abc
Roll number = 1
10 11 12 13 14 15 16 17 18 19
0 1 2 3 4 5 6 7 8 9
20 21
rollno
name
Unions are a concept borrowed from structures and therefore follow the same syntax as structures .
There is a major difference between them in terms of storage .
A union may contain many members of different types ,it can handle only one member at a time.
union union_name
{
data_type member1;
data_type member2;
… …
};
//header files
#include<stdio.h>
#include<conio.h>
//Union declaration
union student
{
// data types & members
int rollno;
char name[20];
};
void main (){union student S1; //Union variable printf(“Input the name of student “);scanf(“%d”,&S1.name);printf(“Input the Roll number of student “);scanf(“%d”,&S1.rollno);printf(“name =%d“S1.name);printf(“Roll number=%d“S1.rollno);getch();}
Input the name of student abc
Input the Roll number of student 1
name = abc
Roll number = 1
10 11 12 13 14 15 16 17 18 19
0 1 2 3 4 5 6 7 8 9
name
rollno
Classes are same as structure but with a small difference ie. Structure are having data only(int or float) but classes are having data and functions together.
The class has a mechanism to prevent direct access to its members ,which is the central idea of object-oriented programming.
Classes are user defined data types.In short structure + functions = classes.
Data
Functions Class
A class definition begin with the keyword class.The body of the class is contained with in the
brace { };
class <name of class>{ private: declaration of variables ; declaration of functions ; public: declaration of variables ; declaration of functions;};
//Header files
#include<iostream.h>
#include<conio.h>
class student //class declaration
{
private:
int rollno; // data members
char name[20];
public:
void getdata(); //functions
//defining member function inside the class definition
void display()
{
cout<<“Name=“<<name<<endl;
cout<<“Roll number=“<<rollno<<endl;
}
};
// defining member functions outside the class definition
void student :: getdata()
{
cout<<“Input the name of student”;
cin>>name;
cout<<“Input the roll number”;
cin>>rollno;
}
main()
{
cout<<“We are in main function “;
student S1; //creat object S1
S1.getdata(); //call member function
S1.display(); //call member function
getch();
}
Input the name of student abc
Input the roll number 1
Name = abc
Roll number = 1