Resets all changes done
git reset --hard
Give a git commit without changing the previous commit message
git commit --amend --no-edit
Modify last commit message
git commit --amend -m "An new updated commit message"
Push to master
git push origin HEAD:refs/for/master
Discard all changes made to a file
discard changes in locally modified file
git restore main.cpp
git delete local branch
git branch --delete old-branch