java script

Write a function `popular(str)` that takes a

string as an argument and returns an array of all of the characters that appear

4 or more times in the string.

Examples:

console.log(popular('pear')); // []

console.log(popular('bananas as marcg')); // [ 'a' ]

console.log(popular('Yes, we have no bananas,or do we have no bananas today!')); // [ 'e', ' ', 'a', 'n' ]