How to Use the Git Merge Command

The git merge command is used to combine changes from different branches into the current branch. It allows you to integrate the changes made in one branch into another branch. The basic syntax of git merge is as follows:

git merge <branch>

Here’s a step-by-step explanation of how git merge works:

1. Start with the following commit history:

   A -- B -- C (current branch)
        \
         D -- E -- F (branch to be merged)
   

2. If you want to merge the changes from branch to be merged into the current branch, you can run the following command while on the current branch:

   git merge branch-to-be-merged
   

3. Git will attempt to automatically merge the changes from branch to be merged into the current branch. If the changes do not conflict, Git will create a new merge commit that combines the changes from both branches. The commit history will look like this:

   A -- B -- C -- M (current branch)
        \       /
         D -- E -- F (branch to be merged)
   

   The merge commit M represents the combination of changes from both branches.

4. If there are conflicts between the changes in the two branches, Git will pause the merge process and indicate the conflicting files. You will need to manually resolve the conflicts by editing the files and then complete the merge by running git merge --continue.

It’s important to note that git merge modifies the commit history by creating a new merge commit. The merge commit records the fact that the changes from one branch were integrated into another branch. It’s recommended to use git merge on local branches that haven’t been pushed to a remote repository yet. If you have already pushed the branch to a remote repository, be cautious when using git merge as it can cause conflicts for other users who have based their work on the original branch.

Remember to review the changes made by the merge and resolve any conflicts that may arise during the process. It’s good practice to test the merged code to ensure that it functions as expected before pushing the changes to a shared repository.