Creating a New Git Branch from an Existing Branch

How can you create a new branch in your Git repository based on an existing branch?

The Solution

To create a new branch, Git will automatically use the currently checked-out branch as a base. Here’s how to create a new branch from an existing branch.

Steps

1. Check Out the Base Branch:
   First, ensure you are on the branch you want to base your new branch on. If you are already on this branch, you can skip this step.

   git checkout dev

2. Create the New Branch:
   Use the git checkout -b command to create and switch to the new branch. If you are already on the base branch (e.g., dev), simply run:

   git checkout -b feature

If you are on a different branch (e.g., main), specify the base branch as follows:

   git checkout -b feature dev

This command creates a new branch named feature based on dev and switches to it.

3. Push the New Branch to the Remote Repository:
   To push the new branch to the remote repository and set up tracking, use:

   git push -u origin feature

The -u flag sets the upstream tracking information, ensuring that your local feature branch is linked to the remote feature branch.

4. Work on the New Branch:
   Now you can work on the new feature branch and commit your changes without affecting the dev branch.
5. Merge the Feature Branch Back to the Base Branch:
   Once you have completed the work on the feature branch, you can merge it back into the dev branch.

• Switch to the dev branch: git checkout dev
• Merge the feature branch into dev: git merge feature If there are no new commits on dev since the creation of feature, Git will perform a fast-forward merge. If there are new commits, Git will create a new merge commit, and you may need to resolve any merge conflicts that arise.

Summary of Commands

1. Check out the base branch (if not already on it):

   git checkout dev

2. Create and switch to the new branch:

• If already on the base branch:
  sh git checkout -b feature
• If on a different branch:
  sh git checkout -b feature dev

2. Push the new branch to the remote repository:

   git push -u origin feature

4. Merge the feature branch back to the base branch:

   git checkout dev
   git merge feature

By following these steps, you can effectively create a new branch from an existing branch, work on it, and then merge your changes back into the base branch when your work is complete.