Why diffing matters in Git - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the command to see changes between your working directory and the staging area.

Git

git [1]

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

Astatus

Blog

Cdiff

Dcommit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'git status' instead of 'git diff' to see changes.

The git diff command shows the differences between your current files and the staging area.

2fill in blank

medium

Complete the command to compare changes between two commits.

Git

git diff [1] [2]

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

AHEAD

Bbranch

Ccommit2

Dcommit1

Attempts:

3 left

💡 Hint

Common Mistakes

Using branch names without specifying commits.

To compare two commits, you specify their IDs after git diff. Here, you start with the first commit ID.

3fill in blank

hard

Fix the error in the command to show changes staged for the next commit.

Git

git diff --[1]

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

Aadded

Bstaged

Ccommit

Dcached

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--staged' which is not a valid git option.

The correct option to see staged changes is --cached. It shows what is ready to be committed.

4fill in blank

hard

Fill both blanks to create a diff of changes between the current branch and the main branch.

Git

git diff [1] [2]

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

Amain

Bmaster

CHEAD

Dorigin

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'origin' instead of branch names.

HEAD refers to your current branch, and main is the main branch. This command compares your current work with main.

5fill in blank

hard

Fill all three blanks to create a diff that shows changes introduced by the last commit.

Git

git diff [1]~1 [2] -- [3]

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

AHEAD

C.

Dmaster

Attempts:

3 left

💡 Hint

Common Mistakes

Using branch names instead of HEAD references.

This command compares the previous commit (HEAD~1) with the last commit (HEAD) and limits the diff to the current directory (.).

Practice

1. What is the main purpose of using git diff in a project?

easy

A. To delete files from the repository

B. To create a new branch

C. To merge two branches automatically

D. To see the exact changes made between file versions

Solution

1. Step 1: Understand the function of git diff

   git diff shows differences between file versions or commits.

2. Step 2: Identify what git diff does not do

   It does not delete files, merge branches, or create branches.

3. Final Answer:

   To see the exact changes made between file versions -> Option D

4. Quick Check:

   Diffing = showing changes [OK]

Hint: Diff means showing changes between versions [OK]

Common Mistakes:

• Confusing diff with branch creation
• Thinking diff deletes files
• Assuming diff merges branches

2. Which of the following is the correct command to see unstaged changes in your working directory?

easy

A. git diff

B. git diff --staged

C. git status -s

D. git log

Solution

1. Step 1: Recall the meaning of git diff

   git diff shows unstaged changes in your working directory compared to the last commit.

2. Step 2: Understand other commands

   git diff --staged shows staged changes, git status -s shows status summary, and git log shows commit history.

3. Final Answer:

   git diff -> Option A

4. Quick Check:

   Unstaged changes = git diff [OK]

Hint: Use plain git diff for unstaged changes [OK]

Common Mistakes:

• Using git diff --staged for unstaged changes
• Confusing git status with diff output
• Using git log to see file changes

3. Given the following commands run in a git repository:

echo 'Hello' > file.txt
git add file.txt
echo 'World' >> file.txt
git diff

What will git diff show?

medium

A. The difference showing the addition of 'World' in file.txt

B. The entire content of file.txt

C. No output because all changes are staged

D. An error because file.txt is staged

Solution

1. Step 1: Analyze the commands

   First, 'Hello' is written and staged with git add. Then 'World' is appended but not staged.

2. Step 2: Understand what git diff shows

   git diff shows unstaged changes compared to the index (staged files). So it will show the addition of 'World'.

3. Final Answer:

   The difference showing the addition of 'World' in file.txt -> Option A

4. Quick Check:

   git diff = unstaged changes [OK]

Hint: git diff shows changes after last staging [OK]

Common Mistakes:

• Thinking git diff shows staged changes
• Expecting full file content output
• Assuming git diff errors on staged files

4. You ran git diff but it shows no output even though you edited a file. What is the most likely reason?

medium

A. You forgot to save the file after editing

B. You staged the changes with git add

C. You are on the wrong branch

D. The file is ignored by .gitignore

Solution

1. Step 1: Understand what git diff shows

   git diff shows unstaged changes in saved files.

2. Step 2: Consider why no changes appear

   If the changes are staged with git add, git diff shows no output because there are no unstaged changes.

3. Final Answer:

   You staged the changes with git add -> Option B

4. Quick Check:

   Staged changes = no unstaged diff output [OK]

Hint: Stage changes to clear unstaged diff output [OK]

Common Mistakes:

• Assuming staged changes show in git diff
• Thinking branch affects unstaged diff
• Confusing ignored files with unstaged changes

5. You want to review changes between two commits abc123 and def456. Which command correctly shows the differences?

hard

A. git diff --compare abc123..def456

B. git diff --staged abc123 def456

C. git diff abc123..def456

D. git diff --between abc123 def456

Solution

1. Step 1: Recall correct syntax for comparing commits

   The correct syntax uses two commit hashes separated by two dots: git diff abc123..def456.

2. Step 2: Identify invalid options

   git diff --staged abc123 def456 is invalid syntax, and options with --between or --compare do not exist.

3. Final Answer:

   git diff abc123..def456 -> Option C

4. Quick Check:

   Commit range uses two dots [OK]

Hint: Use two dots between commits for diff [OK]

Common Mistakes:

• Using git diff --staged for commit diffs
• Adding unsupported flags like --between
• Confusing diff syntax with log syntax