Build a Cash Register Project

JavaScript
1

Hi, I’m having problems with this end project. I know the final projects are meant to be personal challenges, I wouldn’t ask for help if I wasn’t desperate.

I did some testing and my code seems to work fine but when I run the final tests there are two points that fail. It’s odd because when I manually modify the values of “cid” and “price” then I see the expected results inside the paragraph element.

These are the two points that I fail:

When price is 19.5 , the value in the #cash element is 20 , cid is [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]] , and the #purchase-btn element is clicked, the value in the #change-due element should be "Status: CLOSED PENNY: $0.5" .

When price is less than the value in the #cash element, total cash in drawer cid is equal to change due, and the #purchase-btn element is clicked, the value in the #change-due element should be "Status: CLOSED" with change due in coins and bills sorted in highest to lowest order.

I should say that I experienced some strange behaviour when running the final tests. Sometimes I only change the values inside “cid” for the purpose of testing, one the two points succeeds but a different one fails.

And here’s my code.

let price = 19.5;
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]
];

let totalMoney = (cid[0][1] + cid[1][1] + cid[2][1] + cid[3][1] + cid[4][1] + cid[5][1] + cid[6][1] + cid[7][1] + cid[8][1]).toFixed(2)

const cash = document.getElementById("cash")
const purchase = document.getElementById("purchase-btn")
const change_due = document.getElementById("change-due")

const change = difference => {
  let hundred = ""
  let twenty = ""
  let ten = ""
  let five = ""
  let one = ""
  let quarter = ""
  let dime = ""
  let nickel = ""
  let penny = ""

  let sum = 0

  for (let i = 1; i <= cid[8][1] / 100; i++) {
    if (difference >= 100) {
      difference -= 100;
      difference = difference.toFixed(2)
      sum += 100;
      hundred = `ONE HUNDRED: $${Number((100*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[7][1] / 20; i++) {
    if (difference >= 20) {
      difference -= 20;
      difference = difference.toFixed(2)
      sum += 20;
      twenty = `TWENTY: $${Number((20*i).toFixed(2))} `;
    }
  }
  for (let i = 1; i <= cid[6][1] / 10; i++) {
    if (difference >= 10) {
      difference -= 10;
      difference = difference.toFixed(2)
      sum += 10;
      ten = `TEN: $${Number((10*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[5][1] / 5; i++) {
    if (difference >= 5) {
      difference -= 5;
      difference = difference.toFixed(2)
      sum += 5;
      five = `FIVE: $${Number((5*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[4][1] / 1; i++) {
    if (difference >= 1) {
      difference -= 1;
      difference = difference.toFixed(2)
      sum += 1;
      one = `ONE: $${Number((1*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[3][1] / 0.25; i++) {
    if (difference >= 0.25) {
      difference -= 0.25;
      difference = difference.toFixed(2)
      sum += 0.25;
      quarter = `QUARTER: $${Number((0.25*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[2][1] / 0.1; i++) {
    if (difference >= 0.1) {
      difference -= 0.1;
      difference = difference.toFixed(2)
      sum += 0.1;
      dime = `DIME: $${Number((0.1*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[1][1] / 0.05; i++) {
    if (difference >= 0.05) {
      difference -= 0.05;
      difference = difference.toFixed(2)
      sum += 0.05;
      nickel = `NICKEL: $${Number((0.05*i).toFixed(2))} `;
    } 
  }
  for (let i = 1; i <= cid[0][1] / 0.01; i++) {
    
    if (difference >= 0.01) {
      difference -= 0.01;
      difference = difference.toFixed(2)
      sum += 0.01;
      penny = `PENNY: $${Number((0.01*i).toFixed(2))}`;
    } 
  }

  let change = hundred.concat(twenty, ten, five, one, quarter, dime, nickel, penny)

  if (difference > 0.00) {
    change_due.innerText = "Status: INSUFFICIENT_FUNDS"
    return
  }
  else if (Number(sum.toFixed(2)) === Number(totalMoney)) {
    change_due.innerText = `Status: CLOSED ${change}`
    return
  }
  else if (difference == 0.00) {
    change_due.innerText = `Status: OPEN ${change}`
    return
  }
}

const buy = () => {
  if (Number(cash.value) < Number(price)) {
    alert("Customer does not have enough money to purchase the item");
    change_due.innerText = "";
  }
  else if (Number(cash.value) === Number(price)) {
    change_due.innerText = "No change due - customer paid with exact cash";
  }
  else {
    change_due.innerText = "";
    let difference = Number(cash.value) - Number(price)
    change(difference)
  }
}

purchase.addEventListener("click", buy)
2

Please post all of the code

3

Global variables like this will break your code

4

Ok, so how should I format this variable?

5

Format? I’m not sure what you mean.

You should get rid of stateful global variables like that. Instead, use local variables

6

Thanks, I moved the variable inside the function and it worked. But… why does this happen?

7

Because after reading and running your code once, the tests only run your function, not any line outside of the function.