First MATLAB program - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

MATLAB

disp([1]);

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

AHello, World!

BHello World

C'Hello, World!'

D"Hello, World!"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use quotes around the text.

Using double quotes instead of single quotes.

In MATLAB, text strings must be enclosed in single quotes to be displayed correctly using disp.

2fill in blank

medium

Complete the code to assign the number 10 to a variable named 'x'.

MATLAB

[1] = 10;

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

A10

Bvalue

Cnum

Dx

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number as a variable name.

Putting the value on the left side.

The variable name 'x' is used to store the value 10.

3fill in blank

hard

Fix the error in the code to correctly display the value of variable 'x'.

MATLAB

disp([1]);

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

A'x'

Bx

Cx;

D"x"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the variable name which prints the letter x instead of its value.

Including a semicolon inside disp which causes an error.

To display the value of variable x, just use its name without quotes or semicolon inside disp.

4fill in blank

hard

Fill both blanks to create a variable 'y' that stores the sum of 5 and 3.

MATLAB

[1] = 5 [2] 3;

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

Ay

B+

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong operator like - or * instead of +.

Using a wrong variable name.

Variable y stores the sum of 5 and 3 using the plus (+) operator.

5fill in blank

hard

Fill all three blanks to create a variable 'z' that stores the product of 4 and 7, then display it.

MATLAB

[1] = 4 [2] 7;
disp([3]);

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

Az

B*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * for multiplication.

Trying to display the variable before assigning it.

Variable z stores 4 times 7 using *, then disp shows its value.

Practice

1. What does the MATLAB command disp('Hello, world!') do?

easy

A. It saves the text Hello, world! to a file.

B. It displays the text Hello, world! on the screen.

C. It creates a variable named Hello, world!.

D. It runs a loop that prints Hello, world! multiple times.

Solution

1. Step 1: Understand the disp function

   The disp function in MATLAB shows text or values on the screen.

2. Step 2: Analyze the input to disp

   The input is a string 'Hello, world!' which means it will print this exact text.

3. Final Answer:

   It displays the text Hello, world! on the screen. -> Option B

4. Quick Check:

   disp('text') shows text [OK]

Hint: disp shows text inside single quotes [OK]

Common Mistakes:

• Thinking disp saves text to a file
• Using double quotes instead of single quotes
• Confusing disp with variable creation

2. Which of the following is the correct syntax to display the message Hello in MATLAB?

easy

A. disp('Hello')

B. display(Hello)

C. disp(Hello)

D. print('Hello')

Solution

1. Step 1: Check the correct function name

   MATLAB uses disp to display messages, not display or print.

2. Step 2: Check the string syntax

   Strings must be inside single quotes in MATLAB, so disp('Hello') is correct.

3. Final Answer:

   disp('Hello') -> Option A

4. Quick Check:

   disp with single quotes is correct [OK]

Hint: Use disp with single quotes for text [OK]

Common Mistakes:

• Using double quotes instead of single quotes
• Using wrong function names like print or display
• Missing quotes around text

3. What will be the output of this MATLAB code?

disp('Welcome to MATLAB!')

medium

A. Welcome to MATLAB!

B. disp('Welcome to MATLAB!')

C. SyntaxError

D. No output

Solution

1. Step 1: Understand disp function behavior

   The disp function prints the string inside the parentheses to the screen.

2. Step 2: Check the string format

   The string is correctly enclosed in single quotes, so it will print exactly as given.

3. Final Answer:

   Welcome to MATLAB! -> Option A

4. Quick Check:

   disp prints string text [OK]

Hint: disp prints text inside single quotes exactly [OK]

Common Mistakes:

• Expecting disp to print the command itself
• Using double quotes causing errors
• Forgetting to use disp function

4. Identify the error in this MATLAB code:

disp(Welcome to MATLAB!)

medium

A. Parentheses are not allowed with disp

B. Missing semicolon at the end

C. disp function does not exist

D. Text is not inside single quotes

Solution

1. Step 1: Check the input to disp

   The text Welcome to MATLAB! is not inside single quotes, so MATLAB treats it as variables or commands.

2. Step 2: Understand string syntax in MATLAB

   Strings must be enclosed in single quotes to be recognized as text.

3. Final Answer:

   Text is not inside single quotes -> Option D

4. Quick Check:

   Strings need single quotes [OK]

Hint: Always put text inside single quotes in disp [OK]

Common Mistakes:

• Omitting quotes around text
• Thinking semicolon is required for disp
• Believing disp is not a function

5. You want to write a MATLAB program that displays two lines:
Hello
and
Welcome to MATLAB
Which code will do this correctly?

hard

A. disp('Hello\nWelcome to MATLAB')

B. disp('Hello')
disp(Welcome to MATLAB)

C. disp('Hello')
disp('Welcome to MATLAB')

D. disp('Hello' + 'Welcome to MATLAB')

Solution

1. Step 1: Check how to display multiple lines

   Using two separate disp calls prints each line separately.

2. Step 2: Analyze each option

   disp('Hello') disp('Welcome to MATLAB') uses two disp calls with correct strings. disp('Hello\nWelcome to MATLAB') tries to use \n inside single quotes which MATLAB does not interpret as newline. disp('Hello') disp(Welcome to MATLAB) misses quotes in second disp. disp('Hello' + 'Welcome to MATLAB') tries to add strings which is invalid in MATLAB.

3. Final Answer:

   disp('Hello') disp('Welcome to MATLAB') -> Option C

4. Quick Check:

   Use separate disp calls for multiple lines [OK]

Hint: Use separate disp lines for multiple messages [OK]

Common Mistakes:

• Using \n inside single quotes expecting newline
• Missing quotes around text
• Trying to add strings with + operator