Build a Cash Register

JavaScript
1

I made the lesson for Build a cash register project and the code seems ok, but the test 12 and 18 don’t pass. ¿What can be happening?

My HTML:

<html>
  <head>
    
  </head>
  <body>
    <input id="cash" type="number" value="0"/> 
    <button id="purchase-btn" type="button">Change</button>
        <p id="change-due"></p>
    <script src="script.js"></script>
  </body>
</html>

My javascript:

let price = 19.50;
let cid = [
  ['PENNY', 1.01],
  ['NICKEL', 2.05],
  ['DIME', 3.1],
  ['QUARTER', 4.25],
  ['ONE', 90],
  ['FIVE', 55],
  ['TEN', 20],
  ['TWENTY', 60],
  ['ONE HUNDRED', 100]
];


const base = [
  ['PENNY', 0.01],
  ['NICKEL', 0.05],
  ['DIME', 0.1],
  ['QUARTER', 0.25],
  ['ONE', 1],
  ['FIVE', 5],
  ['TEN', 10],
  ['TWENTY', 20],
  ['ONE HUNDRED', 100]
];



const totalChange = () => {
  let acum = 0;
  cid.forEach(item => {
    acum+=item[1];
  });

https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures-v8/build-a-cash-register-project/build-a-cash-register
  return acum;
}

const button = document.getElementById('purchase-btn');

const div = document.getElementById('change-due');

const calculateChange = () => {
  let closed = true;
let input = document.getElementById('cash');
  let  cash = parseFloat(input.value);
  if(cash < price) {
    alert("Customer does not have enough money to purchase the item");
  }
  if(cash.toFixed(2) === price.toFixed(2)) {
    div.textContent = "No change due - customer paid with exact cash";
    return;
  }
  let returned = cash-price;
  let cashed = [];
  let cidReversed = cid.reverse();
  base.reverse().forEach((el, index) => {
    if(el[1] < parseFloat(returned.toFixed(2)) && returned > 0) { //Entramos si podemos dar cambio
      if(cidReversed[index][1] >= returned) { //Nos sobra
        let selected = el[1]*Math.floor((returned / el[1]) + 1e-10);
        if(selected > 0.005) {
          cashed.push([el[0],selected]);
          returned -= selected;
          if(cidReversed[index][1] > returned + selected) {
            closed = false;
          }
          for(let i = 0; i< 9; i++) {
            if(cid[i][0] === el[0]) {
              cid[i][1] -= selected;
            }
          } 
        }
      }
      else { //Nos falta
        let selected = cidReversed[index][1];
         if(selected > 0.005) {
          cashed.push([el[0],selected]);
          returned -= selected;
          for(let i = 0; i< 9; i++) {
            if(cid[i][0] === el[0]) {
              cid[i][1] = 0;
            }
          }
        }
      }
    }
  });
  if(Math.abs(parseFloat(returned.toFixed(2))) === 0.00) {
    const word = closed? "CLOSED" : "OPEN";
    div.textContent = "Status: " + word;
    cashed.forEach(el => {
      div.textContent+=" " + el[0] + ": " + "$" + el[1];
    })
  }
   else if(Math.abs(parseFloat(returned.toFixed(2))) > 0) {
      div.textContent = "Status: INSUFFICIENT_FUNDS";
    }
    console.log(cid);
}

button.addEventListener('click', calculateChange);

Thanks in advance.

2

can you also provide a link to the challenge/step?

3

i’ve edited your post to include the link to the project. Always post a link when you need help with an fCC topic.
thanks

Edit: also it seems you have 4 tests failing, not just 2?

4

To test your code I have simulated the failing test like this:

price = 3.26
cash.value = 100
cid = [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]

document.querySelector("#purchase-btn").click()

and it works as expected.

So I then added the previous test

cid = [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]
price = 19.5
cash.value = 20
document.querySelector("#purchase-btn").click()

price = 3.26
cash.value = 100
cid = [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]

document.querySelector("#purchase-btn").click()

and now it gives Status: OPEN PENNY: $96.74000000000001

if this happen is because your code is relying on values that are not reset after each click of the button but are kept between clicks

5

you haven’t mentioned what testing you’ve attempted? For eg, when I attempted a couple of tests, the app wasn’t able to give me the correct values after the 2nd test.
Here’s what I tried:

With the code exactly as you gave it above, I typed in:

32.10

and this gave me the following (which is correct so far):
Change
Status: OPEN TEN: $10 ONE: $2 QUARTER: $0.5 NICKEL: $0.1

After that, I typed in
100
but the result was not correct as it said:

Change
Status: INSUFFICIENT_FUNDS

Please note that I tested these two, one after the other without reloading the page. Give it a try and see.

6

oh yes here, reverse is changing base. Do not have a global value like base that you change each time

7

Thank you very much! It’s the reverse() problem. I thought that reverse was inmutable. Mutability is very important!!