composer requirements code example

Example 1: upgrading composer globally on windows

php composer.phar self-update

Example 2: composer install without dependencies

composer install --ignore-platform-reqs

Example 3: run global packages macos composer

export PATH=~/.composer/vendor/bin:$PATH

Example 4: 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

Example 5: composer update

php composer.phar update