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JavaScript

Scott Rushford
Scott Rushford
1,724 Points

Cannot find issue with function for iterating array numbers, adding them, evaluating, and returning largest index.

In this code, I have been able to get to where all items in the array are able to be utilized individually, but I cannot seem to get them to add and evaluate. It appears I am only returning the first number of the array in each sequence. I tried to put many console.log markers to walk it through, but I am baffled.
The goal is to return the actual credit card number with the highest sum of all its digits. Two are the same, but the code must return the most recent. Any ideas to what I am missing?

Steven Parker
Steven Parker
215,958 Points

When posting code, to keep the comments and code separated (and preserve structure in general), use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down:

Or watch this video on code formatting.

Scott Rushford
Scott Rushford
1,724 Points
var cards = 
    ['5865-2600-5889-0555', '4779-598666-3666', '4252-278553-7978' ,'4556-4242-9283-2260'];  // card numbers used console.log(cards, "1");  // raw data

  function maxCardSum(card){             // function...returns card when called
  var resultMaxSum = 0;                       // max sum of card to be used
  var currentSum = 0;                          // counter of current card add
  var newCards = [];                            // reassigning modified cards to array
  var resultCard;

  for (var i = 0; i < cards.length; i++){            // iterate through 
    newCards[i] = cards[i].replace(/-/g, ""); // R&R dashes with ""
    console.log(newCards[i], "2");               // update ... string
    newCards[i] = newCards[i].split("");     // split to separate
    console.log(newCards[i], "3");             // update now an object   
    //newCards[i] = newCards[i].toString();
    // console.log(typeof newCards[i], "4");
   // for loop on the cards
       for (var j = 0; j < newCards.length; j++){    // nested loop
       console.log(newCards[j], "5");                // currently an object
       currentSum += parseInt(newCards[j]);           // adding all on string to currentSum ... does not work...
       console.log(newCards[j], "6");                   // update object
       console.log(currentSum, "7");                    // update number
       } if (resultMaxSum <= currentSum){
             resultMaxSum = currentSum;                 // biggest card updated to this
             resultCard = cards[i];}                    // calculation of max reassigned
   }
   return resultCard;                                       // returns resultCard as qualifying card
}
 maxCardSum(cards);                                       // function maxCardSum,  pass in cards
console.log("The credit card number with the max sum of all numbers is: " + resultCard);

1 Answer

Steven Parker
Steven Parker
215,958 Points

The final log statement is attempting to print an internal variable of the maxCardSum function, maybe it was originally inside the function and moved? But now you can capture the returned value and display that instead:

var max = maxCardSum(cards);    // capture the returned value in "max"
console.log("The credit card number with the max sum of all numbers is: " + max);
Scott Rushford
Scott Rushford
1,724 Points

Thanks Steven! This definitely showed me a pretty big deficit in my code. I was able to make additional changes and it is working well now!!