找到node_modules/angular-cli/lib/config/schema.json
default值就是默认的端口
"serve": { "description": "Properties to be passed to the serve command", "type": "object", "properties": { "port": { "description": "The port the application will be served on", "type": "number", "default": 4200 }, "host": { "description": "The host the application will be served on", "type": "string", "default": "localhost" } } }}也可以通过命令行方式修改， 如：
ng serve --port 4201
