Exact Change - returning different output in freeCodeCamp test than codepen

[Shooshte]

Exact Change

https://www.freecodecamp.com/challenges/exact-change

Issue Description

When I run my code locally, or in codepen it returns the required output. When I run in on the challenge page it returns a different result (I am logging output to console to see the results).

The result in the freecodecamp test is:
[["PENNY",0.49000000000000027]]

The result in codepen is:
[["QUARTER", 0.5]]

Browser Information

MacOs El Capitan, Latest Google Chrome, Desktop

Your Code

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

function neededMoney(price, cash) {
    return cash - price;
}

function getSum(money) {
    var total = 0;
    for(var unit in money) {
        total += money[unit][1];
    }
    return total;
}

function getNotes(neededChange, cid) {
    var returnChange = [];
    var neededMonies = neededChange;
    //Reverse CID array
    cid.reverse();
    //For every unit of money in drawer
    for(var money in cid) {
        //Check the type of money
        switch(cid[money][0]) {
            case "ONE HUNDRED":
                var notes = ["ONE HUNDRED", 0];
                //Check how many bills we have
                var numberOfNotes = cid[money][1] / 100;
                //If we have bills
                if(numberOfNotes >= 1) {
                    //For every bill
                    for(var x = 0; x < numberOfNotes; x++) {
                        //If we need more bills
                        if(neededMonies >= 100) {
                            neededMonies -= 100;
                            notes[1] += 100;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "TWENTY":
                var notes = ["TWENTY", 0];
                var numberOfNotes = cid[money][1] / 20;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 20) {
                            neededMonies -= 20;
                            notes[1] += 20;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "TEN":
                var notes = ["TEN", 0];
                var numberOfNotes = cid[money][1] / 10;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 10) {
                            neededMonies -= 10;
                            notes[1] += 10;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "FIVE":
                var notes = ["FIVE", 0];
                var numberOfNotes = cid[money][1] / 5;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 5) {
                            neededMonies -= 5;
                            notes[1] += 5;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "ONE":
                var notes = ["ONE", 0];
                var numberOfNotes = cid[money][1] / 1;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 1) {
                            neededMonies -= 1;
                            notes[1] += 1;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "QUARTER":
                var notes = ["QUARTER", 0];
                var numberOfNotes = cid[money][1] / 0.25;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 0.25) {
                            neededMonies -= 0.25;
                            notes[1] += 0.25;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "DIME":
                var notes = ["DIME", 0];
                var numberOfNotes = cid[money][1] / 0.1;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 0.1) {
                            neededMonies -= 0.1;
                            notes[1] += 0.1;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "NICKEL":
                var notes = ["NICKEL", 0];
                var numberOfNotes = cid[money][1] / 0.05;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 0.05) {
                            neededMonies -= 0.05;
                            notes[1] += 0.05;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
            case "PENNY":
                var notes = ["PENNY", 0];
                var numberOfNotes = cid[money][1] / 0.01;
                if(numberOfNotes >= 1) {
                    for(var x = 0; x < numberOfNotes; x++) {
                        if(neededMonies >= 0.00) {
                            neededMonies -= 0.01;
                            notes[1] += 0.01;
                        }
                    }
                    if(notes[1] > 0) {
                        returnChange.push(notes);
                    }
                }
                break;
        }
    }
    //If we don't have enough money in drawer
    if (getSum(cid) == neededChange) {
        return 'Closed';
    }
    else if(getSum(returnChange) < neededChange) {
        return 'Insufficient Funds';
    }
    else {
        return returnChange;
    }
}

checkCashRegister(19.50, 20.00, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 1.00], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]);

[ghost]

I copy pasted your code in FreeCodeCamp editor in assignment and in codepen.

1. FreeCodeCamp example ~ 2 examples won't work and your var notes, var numberOfNotes are repeating with var everytime.
   
2. Codepen ~ Same result as above. No errors, output is the same.
   

Maybe I did something wrong in copy/paste so others feel free to try it out too. This is what I got.

[dhcodes]

@Shooshte This is likely caused by how JS (and possibly even FCC and codepen) handles floating point integers. You can read more here: http://floating-point-gui.de/.

While I'm not sure how to remedy it for your code, someone in the HelpJavascript may be able to help.

This has been discussed some in #8162 and #10074

@dayfiri you can see the difference if you use the 4th test.

[Shooshte]

@dhcode

I managed to avoid the issue by multiplying the floats with 10000, and then dividing the result before printing out the output.