30 Days of Javascript 4 - Counter2

Write a function createCounter. It should accept an initial integer init. It should return an object with three functions.

The three functions are:

increment() increases the current value by 1 and then returns it. decrement() reduces the current value by 1 and then returns it. reset() sets the current value to init and then returns it.

Example 1:

Input: init = 5, calls = [“increment”,”reset”,”decrement”] Output: [6,5,4] Explanation: const counter = createCounter(5); counter.increment(); // 6 counter.reset(); // 5 counter.decrement(); // 4 Example 2:

Input: init = 0, calls = [“increment”,”increment”,”decrement”,”reset”,”reset”] Output: [1,2,1,0,0] Explanation: const counter = createCounter(0); counter.increment(); // 1 counter.increment(); // 2 counter.decrement(); // 1 counter.reset(); // 0 counter.reset(); // 0

/**
 * @param {integer} init
 * @return { increment: Function, decrement: Function, reset: Function }
 */
var createCounter = function (init) {
  let num = init;
  return {
    increment: function () {
      num++;
      return num;
    },
    decrement: function () {
      num--;
      return num;
    },
    reset: function () {
      num = init;
      return num;
    },
  };
};

/**
 * const counter = createCounter(5)
 * counter.increment(); // 6
 * counter.reset(); // 5
 * counter.decrement(); // 4
 */

The createCounter function accepts an initial integer init as a parameter. It initializes a num variable to store the current value of the counter.

The increment function increments the num by 1 using the ++ operator and then returns the updated value. The decrement function decrements the num by 1 using the -- operator and then returns the updated value. The reset function sets the num back to the initial value init and then returns it.