Merge pull request #1217 from Manish4Kumar/master

Create File_Handling.cpp

File_Handling.cpp

@@ -0,0 +1,171 @@
+File Handling through C++ Classes
+In C++, files are mainly dealt by using three classes fstream, ifstream, ofstream available in fstream headerfile. 
+ofstream: Stream class to write on files 
+ifstream: Stream class to read from files 
+fstream: Stream class to both read and write from/to files. 
+
+1. passing file name in constructor at the time of object creation 
+2. using the open method 
+
+For e.g.  
+Open File by using constructor 
+ifstream (const char* filename, ios_base::openmode mode = ios_base::in); 
+ifstream fin(filename, openmode) by default openmode = ios::in 
+ifstream fin(“filename”);
+
+Open File by using open method 
+Calling of default constructor 
+ifstream fin;
+fin.open(filename, openmode) 
+fin.open(“filename”); 
+
+
+Modes :  
+
+Member Constant	Stands For	Access
+in *	input	File open for reading: the internal stream buffer supports input operations.
+out	output	File open for writing: the internal stream buffer supports output operations.
+binary	binary	Operations are performed in binary mode rather than text.
+ate	at end	The output position starts at the end of the file.
+app	append	All output operations happen at the end of the file, appending to its existing contents.
+trunc	truncate	Any contents that existed in the file before it is open are discarded.
+Default Open Modes :  
+
+ifstream	ios::in
+ofstream	ios::out
+fstream	ios::in | ios::out
+Problem Statement : To read and write a File in C++. 
+Examples: 
+
+Input : 
+Welcome in Manishkumar. Best way to learn things.
+-1
+Output : 
+Welcome in Manishkumar. Best way to learn things.
+Recommended: Please try your approach on {IDE} first, before moving on to the solution.
+Below is the implementation by using ifsream & ofstream classes.  
+
+
+/* File Handling with C++ using ifstream & ofstream class object*/
+/* To write the Content in File*/
+/* Then to read the content of file*/
+#include <iostream>
+
+/* fstream header file for ifstream, ofstream,
+  fstream classes */
+#include <fstream>
+
+using namespace std;
+
+// Driver Code
+int main()
+{
+    // Creation of ofstream class object
+    ofstream fout;
+
+    string line;
+
+    // by default ios::out mode, automatically deletes
+    // the content of file. To append the content, open in ios:app
+    // fout.open("sample.txt", ios::app)
+    fout.open("sample.txt");
+
+    // Execute a loop If file successfully opened
+    while (fout) {
+
+        // Read a Line from standard input
+        getline(cin, line);
+
+        // Press -1 to exit
+        if (line == "-1")
+            break;
+
+        // Write line in file
+        fout << line << endl;
+    }
+
+    // Close the File
+    fout.close();
+
+    // Creation of ifstream class object to read the file
+    ifstream fin;
+
+    // by default open mode = ios::in mode
+    fin.open("sample.txt");
+
+    // Execute a loop until EOF (End of File)
+    while (fin) {
+
+        // Read a Line from File
+        getline(fin, line);
+
+        // Print line in Console
+        cout << line << endl;
+    }
+
+    // Close the file
+    fin.close();
+
+    return 0;
+}
+Below is the implementation by using fstream class. 
+
+
+/* File Handling with C++ using fstream class object */
+/* To write the Content in File */
+/* Then to read the content of file*/
+#include <iostream>
+
+/* fstream header file for ifstream, ofstream,
+   fstream classes */
+#include <fstream>
+
+using namespace std;
+
+// Driver Code
+int main()
+{
+    // Creation of fstream class object
+    fstream fio;
+
+    string line;
+
+    // by default openmode = ios::in|ios::out mode
+    // Automatically overwrites the content of file, To append
+    // the content, open in ios:app
+    // fio.open("sample.txt", ios::in|ios::out|ios::app)
+    // ios::trunc mode delete all content before open
+    fio.open("sample.txt", ios::trunc | ios::out | ios::in);
+
+    // Execute a loop If file successfully Opened
+    while (fio) {
+
+        // Read a Line from standard input
+        getline(cin, line);
+
+        // Press -1 to exit
+        if (line == "-1")
+            break;
+
+        // Write line in file
+        fio << line << endl;
+    }
+
+    // Execute a loop until EOF (End of File)
+    // point read pointer at beginning of file
+    fio.seekg(0, ios::beg);
+
+    while (fio) {
+
+        // Read a Line from File
+        getline(fio, line);
+
+        // Print line in Console
+        cout << line << endl;
+    }
+
+    // Close the file
+    fio.close();
+
+    return 0;
+}