Answers for "update laravel version using composer"

how to update laravel installer

composer global update laravel/installer

update php version in laravel

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

run composer install

how to update composer in laravel

composer global require "laravel/installer:^4.0"