Version control concept (Git) in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is version control?

Version control is a system that records changes to files over time so you can recall specific versions later. It helps teams work together and keeps track of every change made.

beginner

What is Git?

Git is a popular version control system that helps manage changes in files and coordinate work among multiple people. It stores snapshots of your project and allows easy switching between versions.

beginner

Explain the concept of a 'commit' in Git.

A commit is like saving a snapshot of your project at a certain point. It records what changes were made and allows you to go back to that state if needed.

intermediate

What is a branch in Git?

A branch is like a separate path or workspace where you can make changes without affecting the main project. It lets you try new ideas safely and merge them back later.

beginner

Why is version control important for teamwork?

Version control helps teams work together by tracking who made changes, preventing conflicts, and allowing easy merging of everyone's work. It keeps the project organized and safe.

What does a 'commit' in Git represent?

A A deleted file

B A new project folder

C A saved snapshot of changes

D A user account

A commit saves a snapshot of your project changes at a specific time.

Which of the following best describes a 'branch' in Git?

A A separate line of development

B A backup copy of the entire project

C A deleted version

D A user profile

A branch is a separate line of development to work on changes independently.

Why do teams use version control systems like Git?

A To create new programming languages

B To track changes and collaborate safely

C To speed up the internet

D To delete old files automatically

Version control helps teams track changes and work together without conflicts.

What happens when you 'merge' branches in Git?

A You reset the project to the first version

B You delete all branches

C You create a new branch

D You combine changes from different branches

Merging combines changes from different branches into one.

Which command is used to save changes in Git?

A git commit

B git save

C git push

D git branch

The 'git commit' command saves a snapshot of your changes.

Explain how version control helps when multiple people work on the same project.

Think about how you can keep everyone's work organized and safe.

Describe the process and purpose of creating and merging branches in Git.

Imagine working on a new idea without disturbing the main project.

Practice

1. What is the main purpose of using version control systems like Git?

easy

A. To speed up the computer's processor

B. To create graphics and animations

C. To delete old files automatically

D. To save and track changes to files over time

Solution

1. Step 1: Understand version control basics

   Version control systems keep a history of changes made to files, allowing users to track and manage edits.

2. Step 2: Compare options to purpose

   Only To save and track changes to files over time describes saving and tracking changes, which matches the main purpose of Git.

3. Final Answer:

   To save and track changes to files over time -> Option D

4. Quick Check:

   Version control = save and track changes [OK]

Hint: Version control = saving drafts of your work [OK]

Common Mistakes:

• Confusing version control with speeding up hardware
• Thinking it deletes files automatically
• Assuming it creates graphics

2. Which Git command is used to start a new repository in your project folder?

easy

A. git init

B. git commit

C. git add

D. git push

Solution

1. Step 1: Identify command purpose

   git init creates a new Git repository in the current folder, starting version control.

2. Step 2: Check other commands

   git add stages files, git commit saves changes, and git push sends changes to a remote repository.

3. Final Answer:

   git init -> Option A

4. Quick Check:

   Start repo = git init [OK]

Hint: Initialize repo with git init command [OK]

Common Mistakes:

• Using git add to start a repo
• Confusing git commit with git init
• Thinking git push starts a repo

3. What will happen after running these commands in order?

git init
git add file.txt
git commit -m "First commit"

medium

A. file.txt is ignored by Git

B. A new repository is created and file.txt is saved in the first commit

C. The repository is deleted

D. file.txt is deleted from the folder

Solution

1. Step 1: Analyze each command

   git init creates a new repo, git add file.txt stages the file, and git commit saves the staged file as a commit.

2. Step 2: Understand the result

   The file is saved in the repository history as the first commit; nothing is deleted or ignored.

3. Final Answer:

   A new repository is created and file.txt is saved in the first commit -> Option B

4. Quick Check:

   Init + add + commit = save file in repo [OK]

Hint: Init, add, commit = save file snapshot [OK]

Common Mistakes:

• Thinking commit deletes files
• Confusing add with delete
• Assuming file is ignored automatically

4. You ran git commit -m "Update" but got an error saying "nothing to commit". What is the likely cause?

medium

A. You did not stage any files with git add

B. You forgot to run git init

C. You typed the commit message incorrectly

D. Your files are deleted

Solution

1. Step 1: Understand the error message

   "Nothing to commit" means Git sees no changes staged to save.

2. Step 2: Identify missing step

   Before committing, files must be staged with git add. Without staging, commit has nothing to save.

3. Final Answer:

   You did not stage any files with git add -> Option A

4. Quick Check:

   Commit needs staged files [OK]

Hint: Stage files with git add before commit [OK]

Common Mistakes:

• Skipping git add before commit
• Assuming commit message typo causes this error
• Thinking files are deleted

5. You want to save changes to two files, index.html and style.css, but only index.html should be included in the commit. Which sequence of commands achieves this?

hard

A. git commit -m "Update index"

B. git add .
git commit -m "Update index"

C. git add index.html
git commit -m "Update index"

D. git add style.css
git commit -m "Update index"

Solution

1. Step 1: Stage only the desired file

   Using git add index.html stages only that file, excluding others.

2. Step 2: Commit staged changes

   git commit -m "Update index" saves only the staged index.html changes.

3. Final Answer:

   git add index.html git commit -m "Update index" -> Option C

4. Quick Check:

   Stage specific file, then commit [OK]

Hint: Add only files you want before commit [OK]

Common Mistakes:

• Using git add . to stage all files
• Committing without staging
• Adding wrong file by mistake