git diff --staged for staged changes - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What does git diff --staged show?

You have modified a file and then added it to the staging area using git add. What will git diff --staged display?

Git

echo 'Hello' > file.txt
git add file.txt
# Now run: git diff --staged

A Shows the differences between the working directory and the last commit.

B Shows the differences between the last commit and the staged changes.

C Shows the differences between the working directory and the staged changes.

D Shows the differences between the staging area and the remote repository.

💡 Hint

Think about what 'staged' means in Git and what you want to compare.

git diff --staged (or git diff --cached) shows the changes that have been added to the staging area compared to the last commit. It helps you review what will be committed.

🧠 Conceptual

intermediate

Why use git diff --staged before committing?

Which reason best explains why a developer should run git diff --staged before making a commit?

A To reset the staging area to the last commit.

B To see all untracked files in the project directory.

C To compare the current branch with the remote branch.

D To verify exactly what changes are staged and will be included in the commit.

💡 Hint

Think about what you want to check before saving your changes permanently.

Running git diff --staged helps you confirm the exact changes that are staged and ready to be committed, preventing accidental commits of unwanted changes.

❓ Troubleshoot

advanced

Why does git diff --staged show no output after staging changes?

You modified a file and ran git add to stage it. But when you run git diff --staged, nothing is shown. What is the most likely reason?

A You staged the file but then modified it again without adding the new changes.

B The file was never added to the staging area.

C You are running the command in a different repository.

D The file is ignored by .gitignore.

💡 Hint

Consider whether git add actually staged any changes (e.g., no differences from HEAD or ignored file).

git diff --staged shows nothing if there are no differences between the last commit (HEAD) and the staging area. This happens if git add did not stage changes, for example if the file had no actual differences from HEAD or was ignored by .gitignore. Also, if you staged the file but then modified it again without adding the new changes, git diff --staged will show the staged version, not the working directory changes.

🔀 Workflow

advanced

Order the steps to review and commit staged changes using git diff --staged

Put these steps in the correct order to safely commit changes after staging them.

A 4,1,2,3

B 1,4,2,3

C 4,2,1,3

D 1,2,4,3

💡 Hint

Think about the natural flow from editing to committing.

You first make changes (4), then stage them (1), review staged changes (2), and finally commit (3).

✅ Best Practice

expert

Which command combination ensures you only commit staged changes and not unstaged modifications?

You have some changes staged and some unstaged. Which command sequence guarantees that only staged changes are committed?

A git commit -m 'message' && git diff --staged

B git diff --staged && git commit

C git commit -m 'message'

D git commit --only -m 'message'

💡 Hint

By default, what does git commit include?

By default, git commit commits only the staged changes. Unstaged changes remain uncommitted. The --only option is invalid and will cause an error.