This shows the relationship between Objects and Closures

objects-closures.ts

//External state
let z = 5;

//this closure implicitly contains the value of z
let closure = function(x){
  return x + z;
} 

//The above loosely translates to..
class ObjectClosure{
  
  //private state
  z
  
  //The state is "captured" by the object
  constructor(state){
    this.z = state;
  }

  //This is the equivalent of invoking the closure
  invoke(x){
    return x + z
  }
}


console.assert(closure(2) === new ObjectClosure(z).invoke(2))