fork download
copy 
  1. function Chat() {
  2.   const loggingUsers = new Set();
  3.   const loginCount = new Map();
  4.  
  5.   const login = (id) => {
  6.     if (loggingUsers.has(id)) {
  7.       console.log(`User ${id} is already logged in.`);
  8.     } else {
  9.       console.log(`User ${id} has logged in.`);
  10.       loggingUsers.add(id);
  11.       if (!loginCount.has(id)) loginCount.set(id, 0);
  12.     }
  13.   };
  14.  
  15.   const logout = (id) => {
  16.     if (!loggingUsers.has(id)) {
  17.       console.log(`User ${id} is not logged in.`);
  18.     } else {
  19.       console.log(`User ${id} has logged out.`);
  20.       loggingUsers.delete(id);
  21.       loginCount.set(id, loginCount.get(id) + 1);
  22.     }
  23.   };
  24.  
  25.   const isOnline = (id) => loggingUsers.has(id);
  26.   const countOnline = () => loggingUsers.size;
  27.   const countLogins = (id) => loginCount.get(id);
  28.  
  29.   return {
  30.     login,
  31.     logout,
  32.     isOnline,
  33.     countOnline,
  34.     countLogins,
  35.   };
  36. }
  37.  
  38. const myChat = Chat();
  39. myChat.login(3);
  40. myChat.logout(3);
  41. myChat.login(2);
  42. myChat.login(1);
  43. myChat.login(2); // already logged in
  44. myChat.logout(3); // not logged in
  45. console.log(myChat.countOnline()); // 2
  46. console.log(myChat.countLogins(3)); // 1
  47.  
Success #stdin #stdout 0.09s 31524KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
User 3 has logged in.
User 3 has logged out.
User 2 has logged in.
User 1 has logged in.
User 2 is already logged in.
User 3 is not logged in.
2
1
https://ideone.com/dLgUCH
language:
Node.js (node 11.12.0)
created:
10 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!