![#include<iostream.h>
#include<fstream.h>
int main()
{
ofstream outf(“ITEM”);
cout << “enter item name:”;
char name[30];
cin >> name;
outf << name<<“n”;
cout << “enter item cost:”;
WORKING WITH SINGLE FILE](https://image.slidesharecdn.com/cppt-181001075522/85/working-with-files-10-320.jpg)
![#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>
int main()
{
const int SIZE=80;
char line[SIZE];
ifstream fin1, fin2;
fin1.open(“country”);
READING FROM TWO FILES](https://image.slidesharecdn.com/cppt-181001075522/85/working-with-files-13-320.jpg)
working with files
- 1. WORKING WITH FILES N.SURATHAVANI.Msc(Information Technology) NADAR SARAWATHI COLLEGE OF ARTS AND SCIENCETHENI.
- 2. The file is the many data are stored in the particular place in the disk. The many methods are available for storing in the file and retrieving from the file.
- 3. Input stream The input stream is use to supplies data in the program. Output stream The output stream is use to receives data from the file. streams
- 4. File input and output streams Read Data Data input Write Data Data output Disk files Program
- 5. File stream classes Class Contents filebuf To set the buffers to read and write.It contain close() and open() as members. fstreambase Provides operations common to the file streams. Serves as a base for fstream,ifstream and ofstream class. ifstream Provides input operations. Inherites the functions get(),getline(),read(),seekg() and tellg() functions from istream. ofstream Provides output operations. Inherits put(), seekp(),tellp() and write() functions from ostream. fstreams Provides input and output operations. Inherits all functions from istream and ostream classes through iostream.
- 6. Suitable name for the file Data type and structure Purpose Opening method OPENING AND CLOSING A FILE
- 7. FILE CAN BE OPENED IN TWO WAYS: FILE CONSTRUCTOR FUNCTION MEMBER FUNCTION OPEN()
- 8. A filename is used to initialize the file stream object. Create a file stream object to manage the stream using the appropriate class. The class ofstream is used to create the output stream and the class ifstream to create the input stream. Initialize the file object with the desired file name. OPENING FILE USING CONSTRUCTOR
- 9. Disk Output stream outfile Input stream infile TWO FILE STREAMS WORKING ON SEPERATE FILES program Result file Data file
- 10. #include<iostream.h> #include<fstream.h> int main() { ofstream outf(“ITEM”); cout << “enter item name:”; char name[30]; cin >> name; outf << name<<“n”; cout << “enter item cost:”; WORKING WITH SINGLE FILE
- 11. float cost; cin >> cost; outf << cost << “n”; outf.close(); ifstream inf(“ITEM”); inf >> name; Inf >> cost; Cout << “n”; Cout << “item name:” << name << “n”; Cout << “item cost:” << cost << “n”; Inf.close(); Return 0; }
- 12. The function open() can be used to open multiple files that use the same stream object. SYNTAX: OPENING FILE USING OPEN() file-stream-class stream-object; stream-object.open(“filename”);
- 13. #include <iostream.h> #include <fstream.h> #include <stdlib.h> int main() { const int SIZE=80; char line[SIZE]; ifstream fin1, fin2; fin1.open(“country”); READING FROM TWO FILES
- 14. fin2.open(“capital”); for (int i=1; i<=10; i++) { if (fin1.eof() != 0) { cout << “exit from country n”; exit(1); } fin1.getline(line, SIZE); cout << “capital of” << line; if (fin2.eof () !=0)
- 15. { cout << “exit from capital n”; exit (1); } fin2.getline (line,SIZE); cout << line << “n”; } return 0; }
- 16. The ifstream and ofstream constructors and the function open() to create new files as well as to open the existing files. SYNTAX: MORE ABOUT OPEN(): FILE MODES stream-object.open(“filename”,mode);
- 17. The file mode parameter specifies the purpose for which the file is opened. The file mode parameter can take one of such constants defined in the class ios. ios::in for ifstream functions meaning open for reading only. ios::out for ofstream function meaning open for writing only.
- 18. FILE MODE PARAMETERS PARAMETER MEANING ios::app Append to end-of-file ios::ate Go to end-of-file on opening ios::binary Binary file ios::in Open file for reading only ios::nocreate Open fails if the file does not exist ios::noreplace Open fails if the file already exists ios::out Open file for writing only ios::trunc Delete the contents of the file if it exists