Page 338 - computer science (868) class 11
P. 338

Define a class called Result to perform read and write operations on a binary file “marks.dat”.
                Program 3
                              The detail of the class is given as follows:
                              Data Members
                              int roll                :  To store roll number
                              String name             :  To store name of the student
                              double eng, maths, sci   :  To store marks in English, Maths and Science respectively
                              Member Methods
                              void createFile()       :   Accepts roll, name and marks in three subjects and stores it in
                                                        binary file “marks.dat”
                              void printAvg()         :   Reads binary file “marks.dat” and prints average marks obtained
                                                        by each student
                              static void main()      :  Creates object and executes other methods

                1       import java.io.*;
                2       import java.util.*;

                3       class Result
                4       {
                5           int roll;

                6            String name;

                7           double eng, maths, sci;
                8           void createFile() throws IOException
                9           {

                10              // declaring the classes required to create file
                11              // parameter true opens file in append mode

                12              FileOutputStream fo=new FileOutputStream("Marks.dat", true);
                13              DataOutputStream dou= new DataOutputStream(fo);

                14              Scanner sc=new Scanner(System.in);
                15              char ch='y';

                16              while(ch=='y' || ch=='Y')   // loop to store multiple records
                17              {

                18                   System.out.println("Enter roll no, name, marks in English, Maths and
                                      Science");
                19                  // entering data using Scanner class
                20                  roll=sc.nextInt();

                21                  name=sc.next();

                22                  eng=sc.nextDouble();
                23                  maths=sc.nextDouble();
                24                  sci=sc.nextDouble();

                25                  // writing data to buffer using specific write methods of data type




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