undefined imported by the module code example

Example 1: compiler.js:2175 Uncaught Error: Unexpected value 'undefined' imported by the module 'AppRoutingModule' at syntaxError

imports: [
    BrowserModule, 
   ,routing <=Double Comma
   ,FeatureComponentsModule
  ],

Example 2: compiler.js:2175 Uncaught Error: Unexpected value 'undefined' imported by the module 'AppRoutingModule' at syntaxError

imports: [
    BrowserModule
   ,routing <= Missing Comma
   ,FeatureComponentsModule
  ],