The Problem

Declare a function ‘getCounter’, which takes one argument, a number num and returns an object with two methods: ‘increment’ and ‘decrement’. The methods should increase and decrease the original number passed to getCounter, respectively, and return the updated number.

This problem is a bit different, as rather than returning a function, an object with methods is returned. The returned methods have access to the variable count, which is set to the number passed in and is incremented or decremented depending on the method that is called.

//i: number
//o: updated number based on method called 

// declare getCounter, has no params
function getCounter(number) {
  // declare the variable count, assigned the value of number
  let count = number;
  // return an object containing the increment and decrement methods
  return {
    // increment increases count and returns it
    increment: function() {
      count++;
      return count;
    },
    // decrement decreases count and returns it
    decrement: function() {
      count--;
      return count;
    }
  }
}

const counter = getCounter(3);
console.log(counter.increment()); // expected output: 4
console.log(counter.increment()); // expected output: 5
console.log(counter.decrement()); // expected output: 4