**Tell us what’s happening:**

Hi Campers!

I’m struggling a bit with this one and would appreciate the help. I’ve tried to implement a similar solution to the Roman Numerals Calculator. I increment through all the denominations and start with the highest denomination I can give, loop through that denomination until I can’t give anymore, then push that value to an array and increment to the next unit.

It might be easier if you have a look at the comments I’ve made below. I’ve been working on this for a good few hours so maybe I’m a bit too close to the code to notice an obvious error or logic fail! Any advice would be much appreciated.

On another note, what is the convention for writing comments in the code? Should a comment be indented to the same level as the code it’s representing or should it have no indent?

Thank you in advance!

Emma

**Your code so far**

```
function checkCashRegister(price, cash, cid) {
// ARRAY OF ALL DENOMINATIONS AND THEIR VALUES
var units = [
{name: 'ONE HUNDRED', value: 100.00},
{name: 'TWENTY', value: 20.00},
{name: 'TEN', value: 10.00},
{name: 'FIVE', value: 5.00},
{name: 'ONE', value: 1.00},
{name: 'QUARTER', value: 0.25},
{name: 'DIME', value: 0.10},
{name: 'NICKEL', value: 0.05},
{name: 'PENNY', value: 0.01}
];
let changeDue = cash - price;
let checkCid = cid.reduce((acc, cur) => acc + cur[1], 0);
// IF NOT ENOUGH CHANGE
if(checkCid < changeDue){
return {status: "INSUFFICIENT_FUNDS", change: []};
}
// IF CHANGE DUE EXACTLY MATCHES TOTAL CID
else if(checkCid === changeDue){
let due = cid.sort((a, b) => {
return b[1] - a[1];
});
return {status: "CLOSED", change: due};
}
else {
//GET CID IN SAME ORDER AS 'UNITS' ARRAY TO ITERATE THROUGH BOTH AND SELECT VALUES USING 'i'
cid = cid.reverse();
// DEFINE EMPTY ARRAY TO PUSH BELOW DENOM ARRAY TO (IF DENOM NOT EMPTY)
let result = [];
// ITERATE THROUGH UNITS ARRAY
for(let i = 0, len = units.length; i < len; i++){
// DEFINE EMPTY ARRAY FOR EACH UNIT
let denom = [];
//ON A PARTICULAR UNIT, IF CHANGE DUE IS GREATER THAN OR EQUAL TO THE VALUE OF UNIT[i] AND THERE IS CHANGE AVAILABLE:
while(changeDue >= units[i].value && cid[i][1] >= changeDue){
// IF FIRST ITERATION OF WHILE LOOP, DENOM WILL BE EMPTY
if(denom.length === 0){
denom.push(units[i].name);
denom.push(units[i].value);
// IF DENOM NOT EMPTY, INCREMENT THE DENOM BY THE UNIT VALUE
} else{
denom[1] += units[i].value;
}
// DECREMENT THE CHANGE DUE AND THE CID BY THE VALUE YOU'VE JUST ADDED TO DENOM
changeDue -= units[i].value;
cid[i][1] -= units[i].value;
}
// PROVIDING DENOM ISN'T STILL EMPTY(THE WHILE LOOP RAN), PUSH DENOM TO RESULT
if(denom.length === 2){
result.push(denom);
}
}
// ENSURE THE HIGHEST VALUE IN THE 2D ARRAY IS FIRST
result.sort((a,b) => {
return b[1] - a[1];
})
return {status: "OPEN", change: result};
}
}
checkCashRegister(19.5, 20, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]);
```

**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