T7 - Records and files

Question 1

data structure

Answer 1

• is a collection of elementary data types such as integer, real, Boolean, char or string

Question 2

record -

Answer 2

is a data structure consisting of a number of fields which can all be of different types

Question 3

field

Answer 3

• is a single item of data in a record

Question 4

A file -

Answer 4

is able to store a collection of records
only data type is “string”

Question 5

CSV (comma-separated values) file:

Answer 5

Each record is on a new line
Each field is separated by a comma

Question 6

with any text editor

Answer 6

you can create, read and print a CSV file

Question 7

Create a new file: code

Answer 7

names = newFile(“names.txt”)

Question 8

Write mode –

Answer 8

allows writing to a file

Question 9

Append mode –

Answer 9

allows more data to be added to a file

Question 10

Read mode

Answer 10

– only allows the file to be read

Question 11

Reading:

Answer 11

from a text file involves
opening the file, processing each line
then closing the file

Question 12

Here is an algorithm which writes to a text file:

Answer 12

marksFile = open(“marks.txt”)
name = input(“Input student name: “)
mark = input(“Input student mark: “)
marksFile.writeLine(name + “,” + mark + “\n”)
marksFile.close()

Question 13

“\n”

Answer 13

is the newline character indicating then end of this record

Question 14

After opening, must close a file why?

Answer 14

• frees up any memory used by having it open
• Once closed, the file cannot be read from or written to without opening it again

Question 15

To close a file, use: code

Answer 15

myFile.close()