Page 365 - Cs_withBlue_J_C11_Flipbook
P. 365
26 dou.writeInt(roll);
27 dou.writeUTF(name);
28 dou.writeDouble(eng);
29 dou.writeDouble(maths);
30 dou.writeDouble(sci);
31 System.out.print("Continue y/n");
32 ch=sc.next().charAt(0);
33 }
34 // closing the objects transfers data in buffer to file permanently
35 dou.close();
36 fo.close();
37 }
38 void findAvg() throws IOException
39 {
40 // declaring the classes required to read file
41 FileInputStream fi=new FileInputStream("Marks.Dat");
42 DataInputStream di=new DataInputStream(fi);
43 boolean eof=false;
44 double avg;
45 System.out.println("Roll\tName\t\tAverage"); // printing heading
46 System.out.println("---------------------------------------");
47 // try catch block throws End of File exception when the file is not found
in directory
48 // or end of file is encountered
49 try
50 {
51 while(!eof)
52 {
53 roll=di.readInt();
54 name=di.readUTF();
55 eng=di.readDouble();
56 maths=di.readDouble();
57 sci=di.readDouble();
58 avg=(eng+maths+sci)/3;
363
Basic Input/Output and Data File Handling 363

