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

id, title, isRequired, challengeType, forumTopicId

id	title	isRequired	challengeType	forumTopicId
aa2e6f85cab2ab736c9a9b24	Cash Register	true	5	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. Remember to use Read-Search-Ask if you get stuck. Try to pair program. Write your own code.

Currency Unit	Amount
Penny	$0.01 (PENNY)
Nickel	$0.05 (NICKEL)
Dime	$0.1 (DIME)
Quarter	$0.25 (QUARTER)
Dollar	$1 (DOLLAR)
Five Dollars	$5 (FIVE)
Ten Dollars	$10 (TEN)
Twenty Dollars	$20 (TWENTY)
One-hundred Dollars	$100 (ONE HUNDRED)

Instructions

Tests

tests:
  - text: <code>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]])</code> should return an object.
    testString: 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]');
  - text: '<code>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]])</code> should return <code>{status: "OPEN", change: [["QUARTER", 0.5]]}</code>.'
    testString: '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]]});'
  - text: '<code>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]])</code> should return <code>{status: "OPEN", change: [["TWENTY", 60], ["TEN", 20], ["FIVE", 15], ["ONE", 1], ["QUARTER", 0.5], ["DIME", 0.2], ["PENNY", 0.04]]}</code>.'
    testString: '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]]});'
  - text: '<code>checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])</code> should return <code>{status: "INSUFFICIENT_FUNDS", change: []}</code>.'
    testString: '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: []});'
  - text: '<code>checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 1], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])</code> should return <code>{status: "INSUFFICIENT_FUNDS", change: []}</code>.'
    testString: '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: []});'
  - text: '<code>checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])</code> should return <code>{status: "CLOSED", change: [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]}</code>.'
    testString: '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]]});'

Challenge Seed

function checkCashRegister(price, cash, cid) {
  var change;
  // Here is your change, ma'am.
  return change;
}

// 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", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]);

Solution

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;
}