Bug tracking and fixing in Intro to Computing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the value of variable count.

Intro to Computing

count = 5
print([1])

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

ACount

Bcout

Ccount

Dcnt

Attempts:

3 left

💡 Hint

Common Mistakes

Using a misspelled variable name causes a NameError.

Ignoring case sensitivity leads to errors.

The variable count holds the value 5. To print it, use print(count). The other options are misspelled or undefined variables.

2fill in blank

medium

Complete the code to fix the syntax error in the if statement.

Intro to Computing

number = 10
if number [1] 5:
    print("Greater than 5")

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

A=

B==

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using single equals = instead of comparison operators.

Confusing equality == with greater than >.

The if statement needs a comparison operator. > checks if number is greater than 5. Using = causes a syntax error because it is an assignment, not a comparison.

3fill in blank

hard

Fix the error in the loop to correctly print numbers from 0 to 4.

Intro to Computing

for i in range([1]):
    print(i)

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

A4

B5

C6

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 4 in range excludes the number 4 from output.

Confusing inclusive and exclusive ranges.

The range(5) generates numbers 0 to 4. Using 4 would generate 0 to 3, missing 4. Using 5 is correct to include 4.

4fill in blank

hard

Fill both blanks to create a dictionary of squares for numbers greater than 2.

Intro to Computing

squares = {x: x[1]2 for x in range(1, 6) if x [2] 2}

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

A**

B>

C<

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using * instead of ** for squaring.

Using < instead of > in the condition.

The expression x**2 calculates the square of x. The condition x > 2 filters numbers greater than 2. Other options either calculate incorrectly or filter wrong numbers.

5fill in blank

hard

Fill all three blanks to create a dictionary with uppercase keys and values greater than 0.

Intro to Computing

result = [1]: [2] for k, v in data.items() if v [3] 0}

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

Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using k instead of k.upper() for keys.

Using < or == instead of > in condition.

k.upper() converts keys to uppercase. v is the value. The condition v > 0 filters values greater than zero. This creates a dictionary with uppercase keys and positive values.

Practice

1. What is the main purpose of bug tracking in software development?

easy

A. To find and fix errors in the software

B. To add new features to the software

C. To design the user interface

D. To write documentation for users

Solution

1. Step 1: Understand the role of bug tracking

   Bug tracking is used to identify and keep track of errors or problems in software.

2. Step 2: Differentiate from other tasks

   Adding features, designing UI, and writing documentation are separate tasks from bug tracking.

3. Final Answer:

   To find and fix errors in the software -> Option A

4. Quick Check:

   Bug tracking = find and fix errors [OK]

Hint: Bug tracking = finding and fixing errors [OK]

Common Mistakes:

• Confusing bug tracking with adding features
• Thinking bug tracking is for UI design
• Mixing bug tracking with writing documentation

2. Which of the following is the correct way to report a bug?

easy

A. The app crashes when I click the 'Save' button. Steps to reproduce: 1. Open app 2. Click 'Save' 3. Observe crash.

B. The app is bad and doesn't work.

C. Fix the bug in the code immediately.

D. Add more features to the app.

Solution

1. Step 1: Identify a good bug report

   A good bug report clearly describes the problem and how to reproduce it.

2. Step 2: Compare options

   The app crashes when I click the 'Save' button. Steps to reproduce: 1. Open app 2. Click 'Save' 3. Observe crash. gives clear steps and describes the crash. Other options are vague or unrelated.

3. Final Answer:

   The app crashes when I click the 'Save' button. Steps to reproduce: 1. Open app 2. Click 'Save' 3. Observe crash. -> Option A

4. Quick Check:

   Clear bug report = detailed steps [OK]

Hint: Good bug reports include clear steps to reproduce [OK]

Common Mistakes:

• Writing vague bug descriptions
• Confusing bug reporting with fixing
• Reporting unrelated feature requests as bugs

3. Consider this code snippet that causes a bug:

def divide(a, b):
    return a / b

result = divide(10, 0)
print(result)

What will happen when this code runs?

medium

A. It will print 10

B. It will cause a runtime error (division by zero)

C. It will print 0

D. It will print None

Solution

1. Step 1: Analyze the divide function call

   The function tries to divide 10 by 0, which is mathematically undefined.

2. Step 2: Understand Python's behavior on division by zero

   Python raises a ZeroDivisionError at runtime when dividing by zero.

3. Final Answer:

   It will cause a runtime error (division by zero) -> Option B

4. Quick Check:

   Division by zero = runtime error [OK]

Hint: Division by zero causes runtime error in Python [OK]

Common Mistakes:

• Assuming division by zero returns 0
• Thinking it returns None
• Expecting the program to continue without error

4. You have this buggy code:

def find_max(numbers):
    max_num = 0
    for num in numbers:
        if num > max_num:
            max_num = num
    return max_num

print(find_max([-5, -2, -10]))

What is the bug and how to fix it?

medium

A. Remove the for loop

B. Change '>' to '<' in the if condition

C. Return min_num instead of max_num

D. Initialize max_num to first list element instead of 0

Solution

1. Step 1: Understand the bug with negative numbers

   Initializing max_num to 0 causes wrong result when all numbers are negative because 0 is greater than all negatives.

2. Step 2: Fix by initializing max_num to first element

   Set max_num = numbers[0] so comparison starts correctly with actual list values.

3. Final Answer:

   Initialize max_num to first list element instead of 0 -> Option D

4. Quick Check:

   Start max_num with first element for correct max [OK]

Hint: Initialize max with first list item, not zero [OK]

Common Mistakes:

• Assuming zero is always smallest
• Changing comparison direction incorrectly
• Removing loop instead of fixing initialization

5. A team uses a bug tracking tool to manage issues. They notice some bugs are marked 'fixed' but reappear later. What is the best way to prevent this?

hard

A. Assign bugs to multiple developers at once

B. Ignore bugs that reappear after fixing

C. Add thorough testing and verify fixes before closing bugs

D. Close bugs immediately after code change

Solution

1. Step 1: Understand why bugs reappear

   Bugs reappear if fixes are not properly tested or verified before closing.

2. Step 2: Implement thorough testing and verification

   Testing ensures the bug is truly fixed and prevents regression.

3. Final Answer:

   Add thorough testing and verify fixes before closing bugs -> Option C

4. Quick Check:

   Test fixes before closing bugs to prevent reappearance [OK]

Hint: Test fixes carefully before closing bugs [OK]

Common Mistakes:

• Closing bugs without testing
• Ignoring recurring bugs
• Assigning bugs to many developers causing confusion