Switching Branches

Goals

By the end of this lesson you should be able to

• Use the git switch command to switch between branches in a Git repository

The Switch Command

The git switch command can be used to switch between branches.

$ git switch <branch_name>

NOTE: If you read Git documentation on the internet you will encounter many sites that use the git checkout command to switch branches. This command had become overloaded with functionality so the Git developers have recently split its functionality into two new commands, git switch and git restore. You already encounterd git restore in the Undoing Changes lesson. This lesson deals with git switch.

What does it mean to switch branches? Two main things happen:

1. The HEAD pointer now points to the branch that was switched to
2. Git sets the contents of all files in the working tree and index to be the same as those of the commit pointed to by the branch that was switched to.

Let's see this in action. Right now, your commit history looks something like this:

Figure: Initial Branch Configuration

After switching to the mybranch branch it will look like the figure below, and your working tree contents will have chnaged.

Figure: Branch Configuration After Switch

Try it yourself:

Switch to the mybranch branch, and display the log

$ git switch mybranch
Switched to branch 'mybranch'
$ git branch
master
* mybranch

Notice that mybranch is now the active branch as indicated by the * in the output of the git branch command.

Examine the contents of the git-cheat-sheet.txt file. What happened to the lines you added in the previous lesson?!

Git has set the contents of all the files in your working tree to be the same as those of the commit pointed to by the branch you switched to!

This aspect of branches can seem unsettling when you first encounter it. Git beginners sometimes worry about losing work they have done by switching branches, but their worries are unfounded. All the information is still in the repository; Git has simply updated the contents of your working tree.

Let's confirm that by switching back to the master branch:

Switch back to the master branch

$ git switch master
Switched to branch 'master'
$ git branch
* master
mybranch

Confirm that git-cheat-sheet.txt again contains the new lines from the previous lesson.

Enlightenment is Near!

Once you get comfortable with this aspect of Git, you are near to Git enlightenment! Now, when you want to try something experimental in your code you should think nothing of creating a new branch in which to try things out. If things don't go well, you can just delete the branch and resume with whatever state your code was in on the master branch. And what if your experiments do work? You will learn in the next few lessons how to merge changes from one branch into another.

Before moving on, though, let's take a look at the log output as we switch branches…