how to revert changes in github code example

Example 1: undo git

# KEEP CHANGES
git reset --soft HEAD~1

# REMOVE CHANGES
git reset --hard HEAD~1

Example 2: github restore previous commit

# syntax
git revert <commit>
# example
git revert 99a5c5905e12c74725bae64c61efce140662ce24
# where 99a5c59... is the commit (you can check it on github)