I have one ready-made project and I want to use basic functionality of ready-made project into another project. So, I have pasted www folder into another project but giving some popup errors.
Project Root Folder -> platform -> android -> app -> src -> main -> assets -> www
copy this www folder into new project
You can re-use www folder from one project to another project but make sure
www -> cordova.js -> cordova_plugins.js
these two files cordova.js and cordova_plugin.js should not be replaced in another project. Rest all the files can be re-used but not these two because of sometimes may have version difference.
In your case, you can copy all the files from www folder to another project without cordova.js and cordova_plugin.js. It will resolve pop issue.