Composer 2.0 update in ubantu code example

Example 1: update composer ubuntu

##update composer in ubuntu
#update packages
sudo apt-get update
#if you don't have curl install it
sudo apt-get install curl
#download installer
sudo curl -s https://getcomposer.org/installer | php
#move composer.phar file
sudo mv composer.phar /usr/local/bin/composer
#check composer version
composer -v

Example 2: upgrade composer

To update composer command just find location of composer.phar and update as:
 where composer 	#Retrieves you location of your composer.phar
 cd path_to_composer.phar #Move to directory with composer.phar
 php composer.phar self-update	#Update your composer