JS中比Switch...Case更优雅的多条件判断写法

function whatFood(mealtime) {
 let food = '';

 if (mealtime === 'breakfasttime') {
  food = 'egg';
 } else if (mealtime === 'lunchtime') {
  food = 'vegetable'
 } else if (mealtime === 'dinnertime') {
  food = 'fruit'
 } else {
  food = 'cookie'
 }

 return food;
}

function whatFood(mealtime) {
 let food = '';

 switch (mealtime) {
  case 'breakfasttime':
   food = 'egg';
   break;
  case 'lunchtime':
   food = 'vegetable';
   break;
  case 'dinnertime':
   food = 'fruit';
   break;
  default:
   food = 'cookie';
 }

 return food;
}

function whatFood(mealtime) {

 const food = {
  breakfasttime: 'egg',
  lunchtime: 'vegetable',
  dinnertime: 'fruit'
 }

 return food[mealtime] ? food[mealtime] : 'cookie';
}