Module 8: File Handling
Persistent Storage
When a program closes, data stored in variables is lost (RAM is volatile). To save data permanently, we write it to external files (secondary storage).
(Note: In this browser simulator, files are virtual, but the syntax is precisely what you need for the exam.)
Writing to a File
To write data, you must open the file in write mode, write lines, and crucially, close the file when done.
myFile = openWrite("scores.txt")
myFile.writeLine("Alice, 100")
myFile.writeLine("Bob, 85")
myFile.close()Exercise: Logging Data
Open a file called "log.txt" for writing. Ask the user for their name using input, write it to the file, and then close the file.
Reading from a File
To read data, we open in read mode. We often use a while loop with endOfFile() to read every line until there is nothing left.
myFile = openRead("scores.txt")
while NOT myFile.endOfFile()
line = myFile.readLine()
print(line)
endwhile
myFile.close()Exercise: Virtual File Reader
The simulator has a built-in virtual file named "data.txt". Write a program to open it for reading, read all its lines using a WHILE loop, print them to the console, and close the file.