php artisan composer update command code example

Example 1: upgrade composer version

composer self-update

Example 2: update laravel version global

FIRST METHOD :
===============
# uninstall the package
composer global remove laravel/installer

# reinstall
composer global require laravel/installer
  
SECOND METHOD : 
================
  
Just upgraded from Laravel 7 to 8, and running 
  composer global require "laravel/installer:^4.0" 

did the trick for me (i.e., without removeing first)

Example 3: how to update composer in laravel

composer global require "laravel/installer:^4.0"

Example 4: php composer update

php composer.phar update