How to discard selected parts of the local changes?

git checkout -p

To discard only selected parts of your local changes use git checkout -p.

Git will show parts of your local changes one by one and let you decide what to do with that change.

The available actions for the given hunk are:
 y - discard this hunk
 n - do not discard this hunk
 q - quit discarding hunks
 a - discard this and all the remaining hunks in the file
 d - do not discard this hunk nor any of the remaining hunks in the file
 K - leave this hunk undecided, see previous hunk
 g - select a hunk to go to
 / - search for a hunk matching the given regex
 s - split the current hunk into smaller hunks
 e - manually edit the current hunk
 ? - print help

After selecting an action for the given hunk, git will show the next available hunk. In the example below, the first hunk is discarded with typing y and the second hunk kept with n.

git checkout -p

diff --git a/articles_controller.rb b/articles_controller.rb

index ea67e94..99f04b3 100644

--- a/articles_controller.rb

+++ b/articles_controller.rb

@@ -4,7 +4,7 @@ class ArticlesController < ApplicationController

   end

   def show

-    @article = Article.find(params[:id])

+    @article = Article.find(params[:id])

   end

   def new

(1/1) Discard this hunk from worktree [y,n,q,a,d,e,?]? y

diff --git a/math.rb b/math.rb

index 2021dad..bfd1e54 100644

--- a/math.rb

+++ b/math.rb

@@ -1,14 +1,14 @@

 def operation_add(a, b)

-  return a - b

+  return a + b

 end

 def operation_sub(a, b)

-  return a - b

+  return a + b

 end

 def operation_mul(a, b)

-  return a * b

+  return a + b

 end

 def operation_div(a, b)

(1/1) Discard this hunk from worktree [y,n,q,a,d,s,e,?]? n

See git checkout to learn more about it.