if I create a global git ignore in my old repo will it take that into account my next push code example

Example 1: apply gitignore to current commit

#First commit all changes
git rm -r --cached .
git add .
git commit -m ".gitignore updated"

Example 2: how to put files into gitignore

$ echo debug.log >> .gitignore
$ git rm --cached debug.log
rm 'debug.log'
$ git commit -m "Start ignoring debug.log"