how update version laravel code example

Example 1: 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 2: update php version in laravel

"config": {
    "platform": {
        "php": "7.0.7"
    },
    "preferred-install": "dist",
    "optimize-autoloader": true
}

run composer install