reinstall yarn rails code example

Example 1: yarn download ubuntu

curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt update && sudo apt install yarn

Example 2: yarn react install

There are two ways where you can initiate a REACT app.. 
1. Using npm : npm init react-app 
	 example : npm init react-app sampleApp
2. Using yarn : yarn create react-app 
	 example : yarn create react-app sampleApp