小编Jis*_*hnu的帖子

const person = {
  name: 'john',
  age: 25,
  isTeenager: false
}

if (person.name) {
  console.log('name exists')
}

if (person.hasOwnProperty('age')) {
  console.log('age exists')
}

if (Object.prototype.hasOwnProperty.call(person, 'isTeenager')) {
  console.log('isTeenager exists')
}