It differs in node. this.count = 0; will not go to global dictionary, rather into the object for which the top level anonymous function is called. console.log(global.count); // undefined console.log(this); // { count: 0 }

I have a logging framework built on this concept, which allows me to enable/disable logging from various backend/frontend components when needed. Sometimes, when things go wrong in production, it makes sense to conditionally enable logging for certain components and code section to figure out what is happening.