ShortLongShort.js

// Write a function that takes two strings as arguments, determines the length
// of the two strings, and then returns the result of concatenating the shorter
// string, the longer string, and the shorter string once again. You may assume
// that the strings are of different lengths.

const shortLongShort = (str1, str2) => {
  return (str1.length < str2.length ? str1 + str2 + str1 : str2 + str1 + str2);
};

console.log(shortLongShort('abc', 'defgh'));
console.log(shortLongShort('abcde', 'fgh'));
console.log(shortLongShort('', 'xyz'));