Reading/writing collection of records

2. List different methods for record
organization.
Continue with the company class;
Use fixed length of bytes ,
Use fixed number of fields
Use length indicator,
Use delimiter,
Use index.
Dr. Hussien M. Sharaf 2

3. Dr. Hussien M. Sharaf 3
Fixed
length of
bytes
Variable length
Length
indicator
Record
delimiter
Record
index
Fixed
number of
fields

4. A fixed length record file is one in which each record
contains the same number of bytes.
The length must be the max expected length.
Problems:
1. The estimation of max length.
2. The choice of a character to fill the remaining space.
3. Not readable to human eye.
4. Waste of space.
Dr. Hussien M. Sharaf 4
Record 3 Record 4Record 1 Record 2
200 bytes 200 bytes200 bytes 200 bytes

5. A fixed number of fields where each field can be
of variable size.
The count must be the max expected count.
Problems:
1. The estimation of max count.
2. Not readable to human eye.
3. Waste of space in case of an empty field.
Dr. Hussien M. Sharaf 5
Record 3 Record 4Record 1 Record 2
180 bytes 190 bytes210 bytes 250 bytes
6 fields 6 fields6 fields 6 fields

6. To choose a special character that will not appear
within a record and then insert that after each record.
Dr. Hussien M. Sharaf 6
3. Record Delimiter
Problems:
1. The choice of a delimiter character that does not get
in the way of processing (ex. White space is not a
good choice cause the field may contain spaces
within it like “address fields” same for @).
Name EmailID Course
Name EmailID Course
Record1
Record2
n
n

7. Dr. Hussien M. Sharaf 7
4. Length indicator
And
5. Index
will be continued at next
lecture

8. 1. Start by determining Output.
2. List the inputs.
3. Think about processing.

9. Continue using the CompanyInfo class:
[A] Write a method that takes in ostream and
writes to it a company record whose fields
have Keyword = Value
Write a driver to use this class based on the
template Menu.
Dr. Hussien M. Sharaf 9

10. Continue using the CompanyInfo class:
[B] Write a method that takes in istream and
reads from it a company record whose fields
have Keyword = Value
Write a driver to use this class based on the
template Menu.
Dr. Hussien M. Sharaf 10

11. Next week is the deadline.
No excuses.
Don’t wait until last day.
I can help you to the highest limit within the next
3 days.
Dr. Hussien M. Sharaf 11

12. 1. Delete the “bin” and “obj” folders.
2. Compress the solution folder using
winrar.
3. Rename the compressed file as follows:
StudentName_ID_LecExcercise.rar
4. Email to: dr.sharaf@from-masr.com with
your ID in the subject.
Dr. Hussien M. Sharaf 12