Now Composer 2.0 is released, so I want to know how can I easily upgrade to Composer 2.0?
To upgrade Composer to version 2, use the following command:
composer self-update --2
This will instruct the Composer to update itself to version 2. In case your application isn't viable with Composer 2. You can move back to Composer 1 at any time using the below command:
composer self-update --1
Read more about Composer 2.0 here