File Handling in C++ :File Handling in C++ Presentation Slides Created By Gulshan Kumar Hans PGT Computer Science K.V. No.3, Jaipur


File Handling :File Handling Introduction to File Handling Data entered once, required later again Same Data to be used by others Data required again by the same program Files and Streams


Slide 3:Program Files Input Stream Output Stream


I/O Streams :I/O Streams Stream Description cin Standard input stream cout Standard output stream cerr Standard error stream


File i/o Streams :File i/o Streams Stream Classes required for File i/o : ifstream ofstream fstream


ifstream :ifstream Input file stream Class open() is a member function of the class ifstream Inherited functions of ifstream class, from the class istream are get() getline() read() seekg() tellg()


ofstream :ofstream Output file stream Class open() is a member function of the class ofstream Inherited functions of ofstream class, from the class ostream are put() write() seekp() tellp()


fstream :fstream It supports files for simultaneous input and output fstream is derived from ifstream ofstream iostream They are parent classes and fstream is the child class


fstream :fstream Member functions of the class fstream open close close all seekg seekp tellg tellp


Function in C++ :Function in C++ Function:- A function groups a number of program statements into a unit and gives it a name. The function are used to increase the modularity of the programs and packages. After defining a function, we can call defined function inside the main() Process for using a function: Function Prototype (declaring a function) Function Definition (defining a function with operation statements) Function Call ( calling a function inside the main)


Slide 11:#include void line(); //function prototype void main() ( cout << “ the value of function is”; line(); // calling of function } void line() // function definition { cout<< “welcome”; }


Slide 12:Data file handling program – (Input and Output with Multiple objects) #include class person { public: char name[30]; int tel; void getdata(void) { cout>name; cout>tel; } void showdata(void) { cout<< “name is”<< name; cout<<“ tel number is”<< tel; } };


Slide 13:Void main() { person p; char ch; fstream file; file.open(“test. Txt”, ios::app, ios::in, ios::out); do { cout>ch; } while(ch==‘y’ || ch==‘Y’); file.seekg(0); // reset to start file file.read( ( char*)&p, size of (p));


Slide 14:while (!file.eof()) { cout<<“ person is : ”; p.showdata(); // p is a class object and show data is a function file.read( (char *) &p, size of (p)); } }


Slide 15:Take print out of text file and binary file We have speical file name for hardware devices: ofstream outfile; outfile.open(‘ ‘PRN’ ’); // OPEN FOR PRINTER Output.put(variable name);


Slide 16:THANKS