The largest number

Problem

You get a list of loose digits, each one from 0 to 9, and you have to arrange them to build the largest number you can.

With 4, 5, 6 and 1 the answer is 6541: the biggest digit rules, because whatever sits up front is worth more than everything else together.

The rules: every digit is used and none is left out, so if the 4 shows up three times, it shows up three times in the answer. If the list comes in empty, you return 0.

The way in is sorting: put the digits from largest to smallest and stick them together in that order. To stick them together you can start at 0 and, with each digit, multiply what you have by 10 and add the digit.

Watch that last part: you have to return a number, not a string.

Examples

• Three digits

  [1, 2, 3] → 321

• Four out of order

  [4, 5, 6, 1] → 6541

• With a nine

  [1, 2, 3, 9] → 9321

• A repeated digit

  [4, 4, 1, 4] → 4441

Besides these, the challenge has hidden tests that are revealed when you submit your solution.

You start with this

def largest_number(digits):
    pass

function largestNumber(digits) {
}