Writing text files (writetable, fprintf) in MATLAB - Mini Project: Build & Apply

Writing Text Files with writetable and fprintf in MATLAB

📖 Scenario: You work in a small shop and want to save your sales data to a text file so you can share it with your manager.

🎯 Goal: Learn how to write data to text files in MATLAB using writetable and fprintf.

📋 What You'll Learn

Create a table with sales data

Set a filename variable for the output file

Write the table to a text file using writetable

Write formatted sales data lines using fprintf

Display confirmation message after writing files

💡 Why This Matters

🌍 Real World

Saving sales or inventory data to text files is common in shops and businesses to share reports or keep records.

💼 Career

Knowing how to write and format text files is useful for data reporting, exporting results, and communicating between software tools.

1

Create the sales data table

Create a table called salesData with these columns and values:
Product with entries 'Apples', 'Bananas', 'Cherries'
Quantity with values 10, 15, 7
Price with values 1.2, 0.5, 2.0

MATLAB

% Create the salesData table with Product, Quantity, and Price columns
% Your code here

Need a hint?

Use the table function with cell arrays for text and numeric arrays for numbers.

2

Set the filename for the output file

Create a variable called filename and set it to the string 'sales.txt'

MATLAB

salesData = table({'Apples'; 'Bananas'; 'Cherries'}, [10; 15; 7], [1.2; 0.5; 2.0], 'VariableNames', {'Product', 'Quantity', 'Price'});
% Set the filename variable to 'sales.txt'
% Your code here

Need a hint?

Use single quotes for the string in MATLAB.

3

Write the table to a text file using writetable

Use writetable to write the salesData table to the file named by filename with the option 'Delimiter' set to ','

MATLAB

salesData = table({'Apples'; 'Bananas'; 'Cherries'}, [10; 15; 7], [1.2; 0.5; 2.0], 'VariableNames', {'Product', 'Quantity', 'Price'});
filename = 'sales.txt';
% Write the salesData table to the file using writetable with comma delimiter
% Your code here

Need a hint?

Use writetable with the 'Delimiter' option set to ',' to create a CSV style file.

4

Write formatted sales lines using fprintf and display confirmation

Open the file named by filename for writing using fopen, then use a for loop with index i from 1 to height of salesData to write each product line with fprintf in the format: Product: Quantity units at $Price each. Close the file with fclose. Finally, print 'Sales data saved to sales.txt' using fprintf.

MATLAB

salesData = table({'Apples'; 'Bananas'; 'Cherries'}, [10; 15; 7], [1.2; 0.5; 2.0], 'VariableNames', {'Product', 'Quantity', 'Price'});
filename = 'sales.txt';
writetable(salesData, filename, 'Delimiter', ',');
% Open the file, write formatted lines with fprintf in a for loop, close the file, and print confirmation
% Your code here

Need a hint?

Use fopen with 'w' to open for writing, fprintf inside a for loop to write each line, then fclose. Use fprintf without fileID to print confirmation.