Prompt: tackling floating-point imprecision with the CashAmount class

floating-point imprecision

//https://gist.github.com/tim-hr/c9fb047b96d9d36944cec901b7413201

//GOAL: make a class called CashAmount
//input: accepts double values (e.g., 14.72)

// Note: you can do this by converting to pennies for all denominations so you are always working with integers, then converting back to a two-decimal float as needed.
//How to convert: multipy money by 100 REMEMBER to convert back!



class CashAmount {
  constructor(startingMoney) {
    this.cash = startingMoney;
  }
  totalInPennies() {
    return Math.trunc(this.cash * 100);
  }
  //this name could be improved. to get the result in the test, it is using simple addition, not really doubling anything.
  addDoubleAmount(moreMoney) {
    this.cash += moreMoney;
    return this.toDouble();
  }
  // what should the difference be between IN pennies and AS pennies? Why have both?
  totalAsPennies() {
    return this.totalInPennies();
  }
  quantityOfEachDenomination() {
    //Didn't get to this one.
    //set to denominations obj
      //{
      //   'hundreds': 9,
      //   'fifties': 1,
      //   'twenties': 0,
      //   'tens': 1,
      //   'fives': 1,
      //   'ones': 2,
      //   'quarters': 3,
      //   'dimes': 1,
      //   'nickels': 1,
      //   'pennies': 3
      // }
    //if the number is divisible by 100,
      //set the property to the right number of times
      // subtract from the total
    // if the number is divisable by 50...
  }
  toDouble() {
    return this.cash.toFixed(2);
  }
  toDoubleString() {
    return this.toDouble().toString()
  }
}

//TESTS
// const cash = new CashAmount(10.50);
// console.log(cash.totalInPennies()); // -> 1050
// console.log(cash.addDoubleAmount(29.33));
// console.log(cash.totalAsPennies()); // -> 3983

// const cash = new CashAmount(967.93);
// cash.quantityOfEachDenomination() // ->
// {
//   'hundreds': 9,
//   'fifties': 1,
//   'twenties': 0,
//   'tens': 1,
//   'fives': 1,
//   'ones': 2,
//   'quarters': 3,
//   'dimes': 1,
//   'nickels': 1,
//   'pennies': 3
// }

// const cash = new CashAmount(10.50);
// console.log(cash.addDoubleAmount(29.33));
// console.log(cash.toDouble()); // -> 39.83

// const cash = new CashAmount(10.50);
// cash.addDoubleAmount(29.33);
// console.log(typeof cash.toDoubleString()); // -> '39.83'

// const cash = new CashAmount(0.10);
// console.log(cash.addDoubleAmount(0.20));
// console.log(cash.totalInPennies()); //=== 30