创建项目前，安装angular：
npm install -g @angular/cli
创建项目：
ng new angular-tour-of-heroes
启动项目：
ng serve --open或npm start
卸载angular：
npm uninstall -g angular-cli
出现cannot find module ‘xxx’，说明缺xxx模块，之后会自动安装下载：
npm install @angular/core
npm install @angular/platform-browser-dynamic
npm install @angular/compiler-cli
npm install @angular/router
npm install @angular/[email protected]
npm install @angular/[email protected]
//如npm install xxx这样的模式
运行时出现异常Cannot find module ‘@angular-devkit/build-angular’
npm i nyc @angular-devkit/build-angular
