how to ignore modified file in git code example

Example 1: how to undo a modified file in git

# If you want to revert the changes only in current working directory
git checkout -- .

# discard anything (note: you have to be in the directory
# where all of the changes are located)
# or you can use the command on line 9, you can discard anything
# on the repo
git checkout -- *
git checkout -- :/

# or if you check the git status message after modifying a file 
# there is this command 
git restore <file>

Example 2: how to ignore modified file in git

git update-index --assume-unchanged dir-im-removing/