D:\xampputf8\htdocs>composer global update laravel/installerChanged current directory to C:/Users/Administrator/AppData/Roaming/Composer
Composer could not find a composer.json file in C:\Users\Administrator\AppData\R
oaming\Composer
To initialize a project, please create a composer.json file as described in the
https://getcomposer.org/ "Getting Started" section
应该是路径的问题 联系上下文看 ,可能是git未安装(要安装 且把 git的安装路径 及
git的安装路径的bin目录放到path(环境变量)下面) 或者是 应该执行 composer global require "laravel/installer" 而不是 composer global update laravel/installer 这个命令