1.Composer is not a global default installation case, but based on a directory to install the specified project (such as vendor).
2.Composer requires PHP 5.3.2+ or later, and the need to open openssl. Note that you need to enable openssl configuration, we open php.ini in the php directory, extension = php_openssl.dll remove the semicolon in front of it.
3. After the installation is successful, we can (cmd) Enter the command window composer --version command to see if the installation was successful: