Output filename not configured Error in Webpack

Question

I had installed it globally by running npm install webpack -g and I had included it in my project by running npm install webpack --save-dev.

However, on running the

Answer 1

1. create a file @ root directory webpack.config.js
2. paste below code in this file

module.exports = {
  entry: "./app.js",
  output: {
    filename: "bundle.js"
  }, 
  watch: true
}

3. app.js should also in root directory. write below line in app.js file:

document.write('welcome to react v2 app');

REF. https://medium.com/@dabit3/beginner-s-guide-to-webpack-b1f1a3638460#.a64eeonhn