**Tell us what’s happening:**

I tried the immutable approach (at least I think I did) and stayed away from mutating the original “cid” value until the very end, when I needed to copy paste the cash-in-register values. But instead of getting 0.5 pennies, I get 0 pennies. I tried debugging, which led me to discover, that something in the for loop after the switch statement changes the “cid” values globally and I cannot seem to find the solution.

**Your code so far**

```
function checkCashRegister(price, cash, cid) {
let answer = {
status: "",
change: []
};
const priceCopy = price;
const cashCopy = cash;
const cidCopy = cid;
let totalCashInRegister = 0;
let change = cashCopy - priceCopy;
for (let i = 0; i < cidCopy.length; i++) {
totalCashInRegister += cidCopy[i][1];
}
let totalCashInRegisterCopy = totalCashInRegister;
for (let i = (cidCopy.length - 1); i >= 0; i--) {
let currentCurrencyVal = 0;
let val = 0;
let currencyUnit = "";
switch(i) {
case 8:
currentCurrencyVal = 100;
currencyUnit = "ONE HUNDRED";
break;
case 7:
currentCurrencyVal = 20
currencyUnit = "TWENTY";
break;
case 6:
currentCurrencyVal = 10;
currencyUnit = "TEN";
break;
case 5:
currentCurrencyVal = 5;
currencyUnit = "FIVE";
break;
case 4:
currentCurrencyVal = 1;
currencyUnit = "ONE";
break;
case 3:
currentCurrencyVal = 0.25;
currencyUnit = "QUARTER";
break;
case 2:
currentCurrencyVal = 0.1;
currencyUnit = "DIME";
break;
case 1:
currentCurrencyVal = 0.05;
currencyUnit = "NICKEL";
break;
case 0:
currentCurrencyVal = 0.01;
currencyUnit = "PENNY";
break;
}
while (Number(change.toFixed(2)) >= currentCurrencyVal && cidCopy[i][1] >= currentCurrencyVal) {
change -= currentCurrencyVal;
change = Number(change.toFixed(2));
cidCopy[i][1] -= currentCurrencyVal;
cidCopy[i][1] = Number(cidCopy[i][1].toFixed(2));
val += currentCurrencyVal;
val = Number(val.toFixed(2));
}
if (val !== 0) {
answer.change = [...answer.change, [currencyUnit, val]];
}
}
if (change > 0) {
answer.status = "INSUFFICIENT_FUNDS";
answer.change = [];
}
if (change === 0) {
let newVal = 0;
for (let i = 0; i < answer.change.length; i++) {
newVal += answer.change[i][1];
newVal = Number(newVal.toFixed(2));
}
if (newVal == totalCashInRegisterCopy) {
answer.status = "CLOSED";
answer.change = cid;
// answer.change[0][1] = 0.5; <-- quick fix
}
else {
answer.status = "OPEN";
}
}
console.log(answer);
// Here is your change, ma'am.
return answer;
}
// Example cash-in-drawer array:
// [["PENNY", 1.01],
// ["NICKEL", 2.05],
// ["DIME", 3.1],
// ["QUARTER", 4.25],
// ["ONE", 90],
// ["FIVE", 55],
// ["TEN", 20],
// ["TWENTY", 60],
// ["ONE HUNDRED", 100]]
checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]);
```

**Your browser information:**

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.

**Link to the challenge:**

https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/javascript-algorithms-and-data-structures-projects/cash-register/