freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/javascript-algorithms-and-data-structures-projects/cash-register.md

---
id: aa2e6f85cab2ab736c9a9b24
title: Cash Register
challengeType: 5
forumTopicId: 16012
---

# --description--

Design a cash register drawer function `checkCashRegister()` that accepts purchase price as the first argument (`price`), payment as the second argument (`cash`), and cash-in-drawer (`cid`) as the third argument.

`cid` is a 2D array listing available currency.

The `checkCashRegister()` function should always return an object with a `status` key and a `change` key.

Return `{status: "INSUFFICIENT_FUNDS", change: []}` if cash-in-drawer is less than the change due, or if you cannot return the exact change.

Return `{status: "CLOSED", change: [...]}` with cash-in-drawer as the value for the key `change` if it is equal to the change due.

Otherwise, return `{status: "OPEN", change: [...]}`, with the change due in coins and bills, sorted in highest to lowest order, as the value of the `change` key.

<table class='table table-striped'><tbody><tr><th>Currency Unit</th><th>Amount</th></tr><tr><td>Penny</td><td>$0.01 (PENNY)</td></tr><tr><td>Nickel</td><td>$0.05 (NICKEL)</td></tr><tr><td>Dime</td><td>$0.1 (DIME)</td></tr><tr><td>Quarter</td><td>$0.25 (QUARTER)</td></tr><tr><td>Dollar</td><td>$1 (ONE)</td></tr><tr><td>Five Dollars</td><td>$5 (FIVE)</td></tr><tr><td>Ten Dollars</td><td>$10 (TEN)</td></tr><tr><td>Twenty Dollars</td><td>$20 (TWENTY)</td></tr><tr><td>One-hundred Dollars</td><td>$100 (ONE HUNDRED)</td></tr></tbody></table>

See below for an example of a cash-in-drawer array:

```js
[
  ["PENNY", 1.01],
  ["NICKEL", 2.05],
  ["DIME", 3.1],
  ["QUARTER", 4.25],
  ["ONE", 90],
  ["FIVE", 55],
  ["TEN", 20],
  ["TWENTY", 60],
  ["ONE HUNDRED", 100]
]
```

# --hints--

`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]])` should return an object.

```js
assert.deepEqual(
  Object.prototype.toString.call(
    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]
    ])
  ),
  '[object Object]'
);
```

`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]])` should return `{status: "OPEN", change: [["QUARTER", 0.5]]}`.

```js
assert.deepEqual(
  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]
  ]),
  { status: 'OPEN', change: [['QUARTER', 0.5]] }
);
```

`checkCashRegister(3.26, 100, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]])` should return `{status: "OPEN", change: [["TWENTY", 60], ["TEN", 20], ["FIVE", 15], ["ONE", 1], ["QUARTER", 0.5], ["DIME", 0.2], ["PENNY", 0.04]]}`.

```js
assert.deepEqual(
  checkCashRegister(3.26, 100, [
    ['PENNY', 1.01],
    ['NICKEL', 2.05],
    ['DIME', 3.1],
    ['QUARTER', 4.25],
    ['ONE', 90],
    ['FIVE', 55],
    ['TEN', 20],
    ['TWENTY', 60],
    ['ONE HUNDRED', 100]
  ]),
  {
    status: 'OPEN',
    change: [
      ['TWENTY', 60],
      ['TEN', 20],
      ['FIVE', 15],
      ['ONE', 1],
      ['QUARTER', 0.5],
      ['DIME', 0.2],
      ['PENNY', 0.04]
    ]
  }
);
```

`checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])` should return `{status: "INSUFFICIENT_FUNDS", change: []}`.

```js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.01],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 0],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  { status: 'INSUFFICIENT_FUNDS', change: [] }
);
```

`checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 1], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])` should return `{status: "INSUFFICIENT_FUNDS", change: []}`.

```js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.01],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 1],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  { status: 'INSUFFICIENT_FUNDS', change: [] }
);
```

`checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])` should return `{status: "CLOSED", change: [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]}`.

```js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.5],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 0],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  {
    status: 'CLOSED',
    change: [
      ['PENNY', 0.5],
      ['NICKEL', 0],
      ['DIME', 0],
      ['QUARTER', 0],
      ['ONE', 0],
      ['FIVE', 0],
      ['TEN', 0],
      ['TWENTY', 0],
      ['ONE HUNDRED', 0]
    ]
  }
);
```

# --seed--

## --seed-contents--

```js
function checkCashRegister(price, cash, cid) {
  var change;
  return change;
}

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]]);
```

# --solutions--

```js
var denom = [
    { name: 'ONE HUNDRED', val: 100},
    { name: 'TWENTY', val: 20},
    { name: 'TEN', val: 10},
    { name: 'FIVE', val: 5},
    { name: 'ONE', val: 1},
    { name: 'QUARTER', val: 0.25},
    { name: 'DIME', val: 0.1},
    { name: 'NICKEL', val: 0.05},
    { name: 'PENNY', val: 0.01}
];

function checkCashRegister(price, cash, cid) {
 var output = {status: null, change: []};
 var change = cash - price;
 var register = cid.reduce(function(acc, curr) {
 acc.total += curr[1];
 acc[curr[0]] = curr[1];
 return acc;
 }, {total: 0});
 if(register.total === change) {
 output.status = 'CLOSED';
 output.change = cid;
 return output;
 }
 if(register.total < change) {
 output.status = 'INSUFFICIENT_FUNDS';
 return output;
 }
 var change_arr = denom.reduce(function(acc, curr) {
 var value = 0;
 while(register[curr.name] > 0 && change >= curr.val) {
 change -= curr.val;
 register[curr.name] -= curr.val;
 value += curr.val;
 change = Math.round(change * 100) / 100;
 }
 if(value > 0) {
 acc.push([ curr.name, value ]);
 }
 return acc;
 }, []);
 if(change_arr.length < 1 || change > 0) {
 output.status = 'INSUFFICIENT_FUNDS';
 return output;
 }
 output.status = 'OPEN';
 output.change = change_arr;
 return output;
}
```