user profile update

Drupal 8: I was afraid of it but when I start working in it, it's really a cool CMS than the previous version aka Drupal 7. Most of the things are depends on libraries means you need to include required library files in your controller or .module file or etc. and do your work. So I was working on a project in which the client wants to update user data with profile picture programmatically. So here are the steps which I have followed: