Javascript:按编号索引而不是键值遍历对象

var obj = { a: 1, b: 2, c: 3 };
var keys = Object.keys(obj); // 获取对象的键名数组
for (var i = 0; i < keys.length; i++) {
  var key = keys[i];
  var value = obj[key];
  console.log(key, value);
}

var obj = { a: 1, b: 2, c: 3 };
var entries = Object.entries(obj); // 获取对象的键值对数组
for (var i = 0; i < entries.length; i++) {
  var key = entries[i][0];
  var value = entries[i][1];
  console.log(key, value);
}

var obj = { a: 1, b: 2, c: 3 };
var keys = Object.getOwnPropertyNames(obj); // 获取对象的属性名称数组
for (var i = 0; i < keys.length; i++) {
  var key = keys[i];
  var value = obj[key];
  console.log(key, value);
}