Bug tracking and fixing in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a bug in software development?

A bug is an error or flaw in a software program that causes it to behave unexpectedly or incorrectly, like a typo in a recipe that changes the taste of a dish.

beginner

What is the purpose of bug tracking?

Bug tracking helps teams find, record, and manage bugs so they can fix them efficiently, similar to how a checklist helps you keep track of tasks to complete.

beginner

Name a common tool used for bug tracking.

Common bug tracking tools include Jira, Bugzilla, and Trello, which act like digital notebooks to organize and prioritize bugs.

intermediate

What are the main steps in fixing a bug?

The main steps are: 1) Identify the bug, 2) Understand its cause, 3) Write code to fix it, 4) Test the fix, and 5) Deploy the corrected software, like fixing a leak by finding it, patching it, and checking it doesn't drip anymore.

beginner

Why is testing important after fixing a bug?

Testing ensures the bug is truly fixed and no new problems were introduced, similar to tasting food after adjusting a recipe to make sure it’s better and not worse.

What does bug tracking help with?

A Backing up data

B Writing new features only

C Designing user interfaces

D Finding and managing software errors

Bug tracking is specifically for finding and managing software errors to improve the program.

Which of these is NOT a step in fixing a bug?

A Ignore the bug

B Test the fix

C Identify the bug

D Deploy the corrected software

Ignoring the bug is not part of fixing it; all other steps are essential.

Why do developers test software after fixing a bug?

A To add more bugs

B To delete the software

C To make sure the bug is fixed and no new bugs appeared

D To change the software’s color

Testing confirms the fix works and the software remains stable.

Which tool can be used for bug tracking?

A Jira

B Photoshop

C Excel (only for calculations)

D Spotify

Jira is a popular bug tracking tool; others listed are unrelated.

A bug in software is similar to what in cooking?

A A shopping list

B A typo in a recipe

C A clean kitchen

D A perfectly cooked meal

A bug is like a typo in a recipe that causes the dish to turn out wrong.

Explain the process of bug tracking and fixing using a real-life analogy.

Think about how you find and fix mistakes in daily tasks like cooking or homework.

Describe why testing is important after fixing a bug and what could happen if testing is skipped.

Consider what happens if you don’t check your work after fixing a problem.

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