Cash Register not returning precise number

JavaScript
1

Tell us what’s happening:
This function doesn’t return the precise number of pennies. It should return 0.04, but it returns 0.03. The problem is in the while loop. It doesnt do the last iteration even though every condition is true. It literally makes no sense. Please help if you can make sense out of this code. Im very close to smashing my PC. thanks

Your code so far


function checkCashRegister(price, cash, cid) {
    const values = {
        "PENNY": 0.01,
        "NICKEL": 0.05,
        "DIME": 0.1,
        "QUARTER": 0.25,
        "ONE": 1,
        "FIVE": 5,
        "TEN": 10,
        "TWENTY": 20,
        "ONE HUNDRED": 100,
    }

    let change = [];
    let totalSum = 0;
    let returnVal = cash - price;
    let toReturn = returnVal;
    let reversedArr = cid.reverse();

    for (let i = 0; i < reversedArr.length; i++) {
        if (values[reversedArr[i][0]] <= toReturn && reversedArr[i][1] > 0) {
            console.log("working with:", reversedArr[i]);
            let current = 0;
            while (totalSum < returnVal && reversedArr[i][1] > 0 &&
                totalSum + values[reversedArr[i][0]] <= returnVal) {
                totalSum += values[reversedArr[i][0]];
                current += values[reversedArr[i][0]];
                toReturn -= values[reversedArr[i][0]];        
                reversedArr[i][1] -= values[reversedArr[i][0]];
                console.log(totalSum);
                console.log(toReturn);
                console.log(reversedArr[i][1]);
            }

            if (current) {
                change.push([reversedArr[i][0], current]);
            }
        }
    }

    return change;


}

console.log(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]]));

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36.

Challenge: Cash Register

Link to the challenge:

2

Nevermind , I found the solution. It turns out that 25.55 + 0.01 does not equal 25.56 in Javascript.

3

Really, with any language that uses floating point numbers. I’d use an integer number of cents instead of a decimal number of dollars.

4