Javascript cash register critique

Code Feedback
1

This works. I was just wondering if anyone had any thoughts on if it’s good or if it could have been done better.

function checkCashRegister(price, cash, cid) {

let diff = Number((cash-price).toFixed(2));

let sumAll = 0;
cid.forEach(e => sumAll += e[1]);
    
if (diff > sumAll)
    return {status: 'INSUFFICIENT_FUNDS', change: []};

const currencyHash = {'ONE HUNDRED': 100, 'TWENTY': 20, 'TEN': 10, 'FIVE': 5, 'ONE': 1, 'QUARTER': .25, 'DIME': .1, 'NICKEL': .05, 'PENNY': .01};

let changeArr = [];
let sumChange = 0;

cid.slice().reverse().forEach(e => {

    let currencyType = e[0];
    let availableCurrency = e[1];

    while (currencyHash[e[0]] <= Number((diff-sumChange).toFixed(2))
          && availableCurrency > 0 ) {

        sumChange = Number((currencyHash[currencyType]+sumChange).toFixed(2));

        availableCurrency = Number((availableCurrency-currencyHash[currencyType]).toFixed(2));

        if (!changeArr.length || changeArr[changeArr.length-1][0] != currencyType) {
            changeArr.push([currencyType, currencyHash[currencyType]]);
        }
        else 
        {
            changeArr[changeArr.length-1][1] = 
                Number((changeArr[changeArr.length-1][1]+currencyHash[currencyType]).toFixed(2));
        }
    }
});

if (diff != sumChange)
{
    return {status: "INSUFFICIENT_FUNDS", change: []};    
}
else if (diff == sumAll){
    return {status: "CLOSED", change: cid};
}
else {
    return {status: "OPEN", change: changeArr};
}

}

2

Looks good to me nice work

3

It kind of bothers me that I do all the work of building changeArr and it doesn’t get used in every case.

4

Hi, guys!
Here is my own version of the ‘Cash Register’ challenge. I’d like to read you thought about my code. I also tried to comment everything I’ve done in order to understand better what I did.))
So, be free in critique, and thanks. :slight_smile:

  // 1. Create an objetc with denominations to compare:
        let denom = {
          'PENNY': 0.01,
          'NICKEL': 0.05,
          'DIME': 0.1,
          'QUARTER': 0.25,
          'ONE' : 1,
          'FIVE': 5,
          'TEN': 10,
          'TWENTY': 20,
          'ONE HUNDRED': 100,
        }
        
        // 2. Reverse CID array in order to compare and calculate values from bigger to lesser:
        cid.reverse();

        // 3. Declare some Global variables:
        let changeTotal = cash - price;// total change 
        let changeRest = changeTotal;// rest of the total change after calculation inside a for loop

        let totalCID = 0;// total CID
        let restCID = 0;// CID remained after calculation in for loop
        
        let changeArr = [];

        // 4. Iterate trought the CID array
        for(let [cashName,cashVal] of cid){
            // * accumulate cashVal according to the 'denomination';
            let acc = 0; 
            // * create total CID
            totalCID += cashVal;
            
            // * defines the range of 'denomination' we start the calculation:
            if( changeRest >= denom[ cashName ] ){
                // * iteration is made in base if:
                // - total change is bigger than 'denomination' item;
                // - and value of CID 'denomination' item is bigger than 0;
                while( changeRest >= denom[ cashName ] && cashVal){
                    // * Caluclation and rounding the values;
                    // * .toFixed(2) on each calculation means - two digits after the point;
                    // * as .toFixed(2) transform number into the string the '+' sign convert it into the number:
                    cashVal = +( cashVal - denom[ cashName ]).toFixed(2);
                    changeRest = +( changeRest - denom[ cashName ]).toFixed(2);
                    acc = +( acc + denom[ cashName ] ).toFixed(2);
                }
                changeArr.push( [cashName,acc] );  
            }   
        }

        // 5. Declare restCID to compare with in the for loop
        restCID = +( totalCID - changeTotal).toFixed(2);

        //console.log(`total CID : ${totalCID} | rest CID : ${restCID} | change total : ${changeTotal} | change rest : ${changeRest}`);

        // Defines the return object
        if(totalCID === changeTotal && restCID < 1){
            return {status: "CLOSED", change: cid.reverse()};
        }else  if(changeRest > 0){
            changeRest = changeTotal;
            return {status: "INSUFFICIENT_FUNDS", change : []};
        }

        return {status: "OPEN", change: changeArr};

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]]);

5

good job commenting. that’s what I should have done.