git diff for working directory changes - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of git diff after modifying a tracked file?

You have a file app.txt tracked by Git. You change a line in this file but do not stage it. What does git diff show?

Git

git diff

A Shows the line differences between the last committed version and the current modified file.

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

C Shows no output because changes are not staged.

D Shows the commit history of the file.

💡 Hint

Think about what git diff compares by default when no options are given.

git diff by default shows changes in the working directory compared to the index (staging area). Since the file is modified but not staged, it shows the differences between the index and the current file.

🧠 Conceptual

intermediate

Which command shows differences between staged changes and the last commit?

You have modified and staged some files. You want to see what changes are staged compared to the last commit. Which command do you use?

A git diff --cached

B git diff --staged

C Both B and C

D git diff

💡 Hint

There are two equivalent options to show staged changes.

git diff --staged and git diff --cached both show differences between the index (staged files) and the last commit.

❓ Troubleshoot

advanced

Why does git diff show no output after modifying a file?

You edited a tracked file but running git diff shows no output. What could be the reason?

A You have no changes in the working directory.

B The file was staged already, so changes are not in working directory.

C The file is ignored by Git.

D You ran <code>git diff</code> in a different directory.

💡 Hint

Think about what git diff compares by default.

If the file is staged, git diff shows differences between working directory and index. If no changes exist in working directory (because changes are staged), it shows nothing.

🔀 Workflow

advanced

What is the correct sequence to view unstaged changes, stage them, and then view staged changes?

Arrange these commands in the correct order to see unstaged changes, stage them, and then see staged changes.

A 2, 1, 3

B 1, 2, 3

C 3, 2, 1

D 2, 3, 1

💡 Hint

First see unstaged changes, then stage, then see staged changes.

First, git diff shows unstaged changes. Then git add stages them. Finally, git diff --staged shows staged changes.

✅ Best Practice

expert

Which command safely shows all changes including untracked files before committing?

You want to review all changes including unstaged, staged, and untracked files before committing. Which command shows this best?

A git diff

B git diff --name-only

C git diff HEAD

D git status

💡 Hint

Think about which command summarizes all changes and untracked files.

git status shows staged, unstaged changes and untracked files in a clear summary, helping review before commit.