'use strict';

function counter() {
// counter is just a function, it must be invoked to create the closure.
  let total = 0;
// total becomes a private variable, accessable by returned functions

  return {
    increment() {
      total++;
    },
    decrement() {
      total--;
    },
    getTotal() {
      return total;
    }
  }
}
const calc = counter(); // assigning the return value of counter() to calc
// creates the closure and this small module.
calc.increment(); // adds one to total
calc.getTotal(); // => 1
calc.increment(); // adds one to total
calc.getTotal(); // => 2
calc.decrement(); // minus one to total
calc.getTotal(); // => 1