When I make changes to a file in Git, how can I commit only some of the changes? For example, how could I commit only 15 lines out of 30 lines that have been changed in a file?

 

In Git, you can commit only some of the changes within a file using a feature called "partial staging" or "selective staging." This allows you to choose specific lines or chunks of code to include in a commit while leaving other changes in the same file unstaged. Here's how you can do it with an example:

Let's say you have a file called example.txt with 30 lines, and you want to commit only 15 of those lines.

1. Make changes to the file:

   Edit example.txt and make the necessary changes. In this example, let's say you've edited lines 10 to 25.

2. Check the status of your changes:

   Run the following command to see the status of your changes:

   bash

git status

You'll see that example.txt has been modified, but the changes haven't been staged yet.

Stage the specific lines you want to commit:

To stage only lines 10 to 25, you can use the git add -p command, which allows you to interactively stage changes:

bash

git add -p example.txt

Git will show you a series of prompts for each "hunk" of changes (a hunk is a contiguous section of code). You can choose which hunks to stage or leave unstaged.

• To stage a hunk, type y.
• To skip a hunk, type n.

In your case, you would select y for the hunks corresponding to lines 10 to 25.

Verify the staging:

Run git status again to ensure that only the selected lines have been staged for commit.

Commit the staged changes:

Now, you can commit the staged changes:

bash

5. git commit -m "Committing only lines 10 to 25 from example.txt"
   

   This will create a commit with only the selected lines.

By using the git add -p command, you can selectively stage and commit specific lines or changes from a file while leaving other changes in the same file unstaged. This gives you fine-grained control over what gets included in your commits.