Some web demos extended from the hands-ons of the Udemy course GoWebDev

GoWebDemo1:

• Implement a backend which implements session and cookie
• Additional function: count how many times a user have visited this site
• Some notes from this demo:
  1. Reason of "http: multiple response.WriteHeader calls": See: https://stackoverflow.com/questions/27972715/multiple-response-writeheader-calls-in-really-simple-example
  2. Reason that the template cannot use .memberName to get access to the data in a struct Answer: the first letter of member name should be uppercase, which means the struct allows this member to be exported
  3. Reason that u.VisitCount++ cannot work Answer: The dbUsers map does not use reference to user as its value. So when getting user from it and modifying content of that intance, I am actually changing data of a copy of that user not the original one in the map