MATLAB Desktop and Command Window - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to display the text 'Hello, MATLAB!' in the Command Window.

MATLAB

disp([1]);

Drag options to blanks, or click blank then click option'

A'Hello, MATLAB!'

BHello, MATLAB!

C"Hello, MATLAB!"

Ddisp('Hello, MATLAB!')

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use quotes around the text.

Using double quotes instead of single quotes in older MATLAB versions.

The disp function displays text in the Command Window. The text must be enclosed in single quotes to be treated as a string.

2fill in blank

medium

Complete the code to assign the value 10 to a variable named 'x' in the Command Window.

MATLAB

[1] = 10;

Drag options to blanks, or click blank then click option'

Avalue

Bvar

Cx

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number as a variable name.

Putting the value on the left side.

In MATLAB, you assign values to variables using the equals sign. Here, x is the variable name.

3fill in blank

hard

Fix the error in the code to correctly clear the variable 'data' from the workspace.

MATLAB

clear [1];

Drag options to blanks, or click blank then click option'

Adata

B'data'

C"data"

Dclear data

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the variable name.

Typing the whole command inside the blank.

The clear command removes variables by name without quotes. Using quotes causes an error.

4fill in blank

hard

Fill both blanks to create a 1-by-5 vector named 'v' with values from 1 to 5 and display it.

MATLAB

[1] = [2]; disp(v);

Drag options to blanks, or click blank then click option'

Av

B1:5

Czeros

Dones

Attempts:

3 left

💡 Hint

Common Mistakes

Using zeros or ones instead of the range.

Not assigning to a variable.

We assign the vector 1:5 to variable v. The disp function then shows it.

5fill in blank

hard

Fill all three blanks to create a script that prompts the user for their name, stores it in 'userName', and then greets them.

MATLAB

userName = [1]('Enter your name: ', '[2]'); fprintf('Hello, %[3]s!\n', userName);

Drag options to blanks, or click blank then click option'

Ainput

B's'

Cformat

D'string'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the 's' argument in input.

Using wrong format specifier in fprintf.

The input function asks the user for input. The second argument 's' tells MATLAB to treat input as a string. The fprintf uses %s to print the string.

Practice

1. What is the primary purpose of the MATLAB Command Window?

easy

A. To type commands and see immediate results

B. To write and save large programs only

C. To manage files and folders on your computer

D. To create graphical user interfaces

Solution

1. Step 1: Understand the role of the Command Window

   The Command Window is designed for typing commands and instantly seeing their output.

2. Step 2: Compare with other MATLAB features

   Writing large programs is done in the Editor, file management is outside MATLAB, and GUIs are created with special tools.

3. Final Answer:

   To type commands and see immediate results -> Option A

4. Quick Check:

   Command Window = Immediate command input and output [OK]

Hint: Command Window shows instant results of typed commands [OK]

Common Mistakes:

• Confusing Command Window with Editor
• Thinking Command Window manages files
• Assuming Command Window creates GUIs

2. Which of the following is the correct way to display the value of variable x in the Command Window?

easy

A. disp(x)

B. print(x)

C. show(x)

D. echo x

Solution

1. Step 1: Recall MATLAB display functions

   In MATLAB, disp() is the standard function to display variable values in the Command Window.

2. Step 2: Check other options

   print() is for printing figures, show() and echo are not valid display commands for variables.

3. Final Answer:

   disp(x) -> Option A

4. Quick Check:

   Use disp() to display variable values [OK]

Hint: Use disp() to show variable values in Command Window [OK]

Common Mistakes:

• Using print() instead of disp()
• Trying non-existent functions like show()
• Using echo which is not a MATLAB command

3. What will be the output in the Command Window after running the following commands?

x = 5;
y = x + 3;
disp(y)

medium

A. x + 3

B. 53

C. Error

D. 8

Solution

1. Step 1: Calculate the value of y

   Variable x is assigned 5, then y = x + 3 means y = 5 + 3 = 8.

2. Step 2: Understand disp(y) output

   The disp(y) command prints the value of y, which is 8.

3. Final Answer:

   8 -> Option D

4. Quick Check:

   y = 5 + 3 = 8 [OK]

Hint: Add numbers before disp() to get output [OK]

Common Mistakes:

• Concatenating numbers as strings (53)
• Printing expression instead of value
• Expecting an error from correct syntax

4. Identify the error in the following MATLAB command typed in the Command Window:

disp('Hello World)

medium

A. Missing semicolon at end

B. disp function does not exist

C. Missing closing single quote

D. Incorrect use of parentheses

Solution

1. Step 1: Check string syntax

   The string starts with a single quote but does not have a matching closing single quote.

2. Step 2: Verify other syntax elements

   Semicolon is optional, disp is valid, and parentheses usage is correct except for the string quotes.

3. Final Answer:

   Missing closing single quote -> Option C

4. Quick Check:

   Strings need matching quotes [OK]

Hint: Always close quotes in strings [OK]

Common Mistakes:

• Ignoring missing quote errors
• Thinking semicolon is mandatory
• Assuming disp is undefined

5. You want to quickly test a small calculation and see the result without creating a script file. Which MATLAB Desktop feature should you use?

hard

A. Figure Window

B. Command Window

C. Workspace Browser

D. Editor

Solution

1. Step 1: Understand the purpose of each feature

   The Command Window lets you type commands and see results immediately without saving files.

2. Step 2: Compare with other features

   The Editor is for writing scripts, Workspace Browser shows variables, and Figure Window displays plots.

3. Final Answer:

   Command Window -> Option B

4. Quick Check:

   Quick tests = Command Window [OK]

Hint: Use Command Window for quick calculations [OK]

Common Mistakes:

• Trying to run quick code in Editor only
• Confusing Workspace Browser with command input
• Thinking Figure Window runs code