how to upgrade composer in laravel code example

Example 1: how to update laravel installer

composer global update laravel/installer

Example 2: laravel composer update

php composer.phar update

Example 3: how to update composer in laravel

composer global require "laravel/installer:^4.0"

Example 4: laravel 7 upgrade

$>which composer
/usr/local/bin/composer

$>php -d memory_limit=512M /usr/local/bin/composer update
...