对象属性的遍历

遍历对象属性：
1.用for...in...遍历

let person = {
  name: 'henry',
  age: 18,
}

for (let key in person) {
  console.log('键名：' + key + '；键值：' + person[key]);
}

2.借助Object.keys遍历

let person = {
  name: 'henry',
  age: 18,
}

let keys = Object.keys(person);

for (let i = 0; i < keys.length; i++) {
  console.log('键名：' + keys[i] + '；键值：' + person[keys[i]]);
}