Fast-forward merge in Git - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a fast-forward merge in Git?

A fast-forward merge happens when the branch you want to merge has all the new commits ahead of the current branch, so Git just moves the current branch pointer forward without creating a new commit.

beginner

When does Git perform a fast-forward merge automatically?

Git performs a fast-forward merge automatically when the current branch has no new commits since the branch to merge started, meaning the current branch can just move forward to the target commit.

intermediate

How do you prevent Git from doing a fast-forward merge?

You can prevent a fast-forward merge by using the command git merge --no-ff <branch>, which forces Git to create a merge commit even if a fast-forward is possible.

intermediate

What is the visual difference between a fast-forward merge and a regular merge?

A fast-forward merge moves the branch pointer forward in a straight line, while a regular merge creates a new commit that joins two branches, showing a branch and merge structure in the history.

intermediate

Why might you choose to avoid fast-forward merges?

Avoiding fast-forward merges keeps the history clearer by showing when branches were merged, which helps understand the project timeline and review changes better.

What does a fast-forward merge do in Git?

A Reverts the last commit on the current branch

B Creates a new merge commit combining two branches

C Moves the current branch pointer forward without creating a new commit

D Deletes the source branch after merging

A fast-forward merge simply moves the branch pointer forward when no new commits exist on the current branch.

Which command prevents Git from doing a fast-forward merge?

A git merge --ff-only <branch>

B git checkout <branch>

C git rebase <branch>

D git merge --no-ff <branch>

Using --no-ff forces Git to create a merge commit even if a fast-forward is possible.

When is a fast-forward merge NOT possible?

A When the current branch has new commits not in the other branch

B When the branches are identical

C When the source branch is ahead of the current branch

D When the repository is empty

If the current branch has new commits, Git cannot just move the pointer forward; it needs a merge commit.

What does the Git history look like after a fast-forward merge?

A A branch with a merge commit

B A straight line with no merge commits

C Multiple parallel branches

D A detached HEAD state

Fast-forward merges keep history linear without extra merge commits.

Why might developers prefer to create merge commits instead of fast-forward merges?

A To keep a clear record of when branches were merged

B To speed up the merge process

C To delete the source branch automatically

D To avoid conflicts

Merge commits help track the integration points of branches clearly in history.

Explain what a fast-forward merge is and when Git uses it.

Think about how Git moves the branch pointer when no new commits exist on the current branch.

Describe how to force Git to create a merge commit even if a fast-forward merge is possible and why you might want to do that.

Consider how to keep the project history easier to understand.