Legibility vs Cleverness

comprehension.js

// Clever
function comprehension(arr, fn) {
  return arr.reduce((obj, key) => Object.assign(obj, {[key]: fn(key)}), {});
}

// Legible
function comprehension(arr, fn) {
  const obj = {};
  for (key of arr) {
    obj[key] = fn(key);
  }
  return obj;
}