Print how often every digit occurs

Write a function printDigitCounts(digits) that prints how many times every digit occurs in an array.

• digits is an array of whole numbers from 0 to 9. It can be empty.
• Print one line per digit with console log, in the format <digit>: <count>, for example 1: 2.
• Print the lines after you have counted everything, one line per digit, not one line per array element.
• The lines go in the order in which each digit first appears in the array: its insertion order.
• For an empty array print nothing.
• The function returns nothing.
• The interviewer asked you to count with a Map. The tests check only the output; keep to the rule yourself.