how to update composer mac code example

Example 1: install composer mac

curl -sS https://getcomposer.org/installer | php
php composer.phar install
mv composer.phar /usr/local/bin/composer
open -e  ~/.zshrc
// or open -e  ~/.bash_profile
alias composer="php /usr/local/bin/composer"

Example 2: update composer mac

#Ubuntu-Download Composer and create a Phar (PHP Archive) file
$ curl -s https://getcomposer.org/installer | php

#Move it to bin directory
$ sudo mv composer.phar /usr/local/bin/composer

Example 3: composer mac

php composer-setup.php --install-dir=bin --filename=composer