Build a Cash Register Project - Build a Cash Register

JavaScript
1

Tell us what’s happening:

I made all this, and now im stuck, i dont know how to write for, how to search, what, and how much to subsctract from input.value, or should i subsctract from it at all?I dont know what do i even do, i feel so ass about my skills

Your code so far

<!-- file: index.html -->


/* file: script.js */
const status = document.getElementById('status');
const input = document.getElementById('cash');
const output = document.getElementById('change-due');
const purchaseBtn = document.getElementById('purchase-btn');
let price = 1.87;
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 denominations = [
    ['ONE HUNDRED', 100],
    ['TWENTY', 20],
    ['TEN', 10],
    ['FIVE', 5],
    ['ONE', 1],
    ['QUARTER', 0.25],
    ['DIME', 0.1],
    ['NICKEL', 0.05],
    ['PENNY', 0.01]
  ];
const checkResults = () => {
    const cash = parseFloat(input.value);
    const changeNeeded = (cash - price).toFixed(2);
    
    if (cash < price) {
      alert("Customer does not have enough money");
      return;
    }
    
    if (cash === price) {
      output.textContent = "No change needed";
      return;
    }

    let remainingChange = changeNeeded;
    const changeBreakdown = [];
    
    const tempCid = [...cid].reverse();

    for (const [name, value] of denominations) {
      if(input.value >= value){
         input.value -= value;
         
      }
    }
}


purchaseBtn.addEventListener("click", checkResults)

/* file: styles.css */

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36 OPR/115.0.0.0

Challenge Information:

Build a Cash Register Project - Build a Cash Register

2

If you were handed a bunch of money and had to hand me a certain amount from that pile of money, how would you do that by hand?

3

Depending on amount, search what u need and give it.Or what do you mean?

4

I’m not sure what “search what u need” means. Can you be more specific?

5

if u wanted 50$, i would search for it in my pocket for example and give it to you

6

But what if I wanted something that cannot be given as a single bill. Say if I wanted $30.52?

7

give you 30, 0,50, 0,02

8

The US does not have 30 dollar bills and this project does not have 50 cent pieces.

9

These are the denominations that we have. How would you give me $30.52?

10

3 tens 2 quaters 2 pennies

11

That would work. Why did you start with $10 dollar bills?

12

oh 1 twenty 1 ten 2 quaters and 2 pennies

13

Ok, that’s sounding almost like an algorithm. Why did you start with the $20 dollar bill?

14

because its less then the amount before, if i gave u the amount before, it would be too big

15

Brilliant, that is starting to sound like a process we can formalize with some if statements and loops.

After you pick out a $20 to give to me, you would have to still find $10.52, right? So how would you know to pick a $10 bill next?

16

because now 20 is too big, but i dont get, how do i get to it, if the number before is too big, do i write forEach and do index + 1?

17

I wouldn’t worry about any fancy loop methods just yet.

99% of the time, you can do what you need just with if statements and plain old for loops.

18

so like, what do i do?

for(const [name, value] of denominations){
 if(value <= change){
change -= value;
}
}

Or do i write while?

19

That’s not a plain old for loop, but that works too.

Plain old for loop:

for (let i = 0; i < denominations.length; i++) {
}

But yeah, some flavor of for loop over the denominations sounds right to me.

Where are you thinking you might need a while?

20

i think i might need it like in converter we made earlier, but i dont know, we subsctracted value of object while we could, then went to the next object, and so long, until 0