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Topic 8 · Programming

File handling

Why programs store data in files, and how to open, write, read, and close a text file in pseudocode.

Lesson 7 of 7Syllabus 8.3updated October 31, 2026

Why use files?

Variables live in RAM, so their values disappear when the program ends. Storing data in a file keeps it permanently, so it can be loaded the next time the program runs, or used by another program.

Open, use, close

Every file operation follows the same pattern:

  1. 1
    Open
    OPENFILE "scores.txt" FOR WRITE or FOR READ
  2. 2
    Write or read
    WRITEFILE sends a line to the file; READFILE reads the next line into a variable.
  3. 3
    Close
    CLOSEFILE saves the file and frees it for other programs.

Watch out. Opening a file FOR WRITE replaces anything already in it.

Writing to a file

Pseudocode
DECLARE Name : STRING
OPENFILE "names.txt" FOR WRITE
INPUT Name
WRITEFILE "names.txt", Name
CLOSEFILE "names.txt"

Reading from a file

Each READFILE reads the next line of the file into a variable.

Pseudocode
DECLARE FirstLine : STRING
OPENFILE "names.txt" FOR READ
READFILE "names.txt", FirstLine
OUTPUT "The first name is ", FirstLine
CLOSEFILE "names.txt"

Key terms

File
A named collection of data stored permanently on secondary storage.
OPENFILE
Opens a file for reading or writing.
READFILE / WRITEFILE
Reads one line from, or writes one line to, an open file.
CLOSEFILE
Closes a file when the program has finished with it.

Check yourself

Why might a game save high scores to a file instead of a variable?Show answer

Variables are lost when the program closes; a file keeps the scores permanently for next time.

What must happen before a program can read a file?Show answer

The file must be opened with OPENFILE ... FOR READ.

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