module.export = {
  entry: {
    './main1.js',
    './main2.js'
  },
  output: {
    filename: '[name]x.js'
  }
}
//  [name] stand for the value for webpack input js name;
//  in this example, the name stands for `main1x.js` and `main2xjs`
//  and the default Path is ./dist/xxx