test.js

gistfile1.txt

// 1. the sum of digits for one credit card number
function sumCard(num) {
    // get number and change to integer
    var num = num.match(/\d/g).map(Number);
    // find the sum of an array of numbers
    var sum = num.reduce((a, b) => a + b, 0);
    return sum   
}

// 2. get credit card number has the last largest sum of digits
function largestCard(lst) {
    // initialize values
    var sumlst = [];
    var max = 0;
    var maxIndex = 0;
    var maxCardNum = '';
    // as getting the sum values of credit card, new max value and its index is updated. 
    for(item in lst) {
       var addItem = sumlst.push(sumCard(lst[item]));
       if (sumlst[item] >= max){
           max = sumlst[item];
           maxIndex = item;
       }
    }
    maxCardNum = lst[maxIndex]
    return maxCardNum
}

//Input Data
var inputCard = largestCard(['4916-2600-1804-0530', '4779-252888-3972', '4252-278893-7978', '4556-4242-9283-2260']);
//Outout Data
console.log(inputCard)

# -*- coding: utf-8 -*-
# For this challenge, we are interested in finding the credit card number whose digits sum to the largest number. If more than one has the same largest sum of digits, we want the last one in the list with that sum.
# Write a single function that takes one argument. That argument will be an array  of credit card numbers. Assume the array can have any number of credit card numbers and each one is a string of digits and dashes. Your function should return the credit card number that has the largest sum of digits.

# Here is a sample array of credit card numbers:
# ['4916-2600-1804-0530', '4779-252888-3972', '4252-278893-7978', '4556-4242-9283-2260'] 

# In the sample array above, the digits add up to 49, 81, 81, and 64 respectively. Since there are two which have the same sum, the function should return the last one with that sum, in this case '4252-278893-7978'
# Things to accomplish:

# Contain all variables and code needed within a function.
# Have that function take one argument which will be an array of credit card number strings.
# Determine the sum of digits for each credit card number.
# Determine which credit card number has the last largest sum of digits.
# Use a return statement to return the required card number in its’ original form.



def sumCard(num):
    num = sum(map(int, [x for x in filter(str.isdigit, num)]))
    return num


def largestCard(lst):
    #make sum list
    sumLst = [sumCard(x) for x in lst]
    #find index of item which equal to maxVal 
    indices = [x for x in range(len(sumLst)) if sumLst[x] == max(sumLst)]
    #get the last one in the list and get element value
    last = lst[indices[-1]]
    return last


#print code
print(largestCard(['4916-2600-1804-0530', '4779-252888-3972', '4252-278893-7978', '4556-4242-9283-2260']))