。JavaScript中的每个循环都不起作用，有什么想法吗？

Question

const dinner = [{
  name: 'hamburger',
  source: 'meat'
}, {
  name: 'cheese',
  source: 'dairy'
}, {
  name: 'ketchup',
  source: 'plant'
}, {
  name: 'bun',
  source: 'plant'
}, {
  name: 'dessert twinkies',
  source: 'unknown'
}];


const isTheDinnerVegan = arr => {
  arr.every(isVegan);
}

const isVegan = (el) => {
  if (el.source === 'plant') {
    return true;
  }
  return false;
}

console.log(isTheDinnerVegan(dinner));

Answer 1

仅当所有源==='源'时，它才为真。请参考https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every