如何遍历JSON对象数组？

Question

我有需要循环的JSON数据.数据位于标题为"people.json"的文件中,其结构如下所示:

[{"firstname":"John","lastname":"Smith","age":"40"},{"firstname":"Bill","lastname":"Jones","age":"40"}, ...]

我想读取这个文件中的每个对象并保存它(我使用的是Mongoose).这是我到目前为止:

var fs = require('fs');
var Person = require('../models/people');

fs.readFile('./people.json', 'utf8', function (err,data) {
    var i;
    for(i = 0; i < data.length; i++) {
        var newPerson = new Person();
        newPerson.firstname = data[i].firstname;
        newPerson.lastname = data[i].lastname;
        newPerson.age = data[i].age;
        newPerson.save(function (err) {});
    }
});

我不能让这个工作.我究竟做错了什么？

Answer 1

fs.readFile('./people.json', 'utf8', function (err,data) {
  data = JSON.parse(data); // you missed that...
  for(var i = 0; i < data.length; i++) {
    var newPerson = new Person();
    newPerson.firstname = data[i].firstname;
    newPerson.lastname = data[i].lastname;
    newPerson.age = data[i].age;
    newPerson.save(function (err) {});
  }
});

Answer 2

ES6 for..of也可以这样做.

fs.readFile('./people.json', 'utf8', function (err,data) {
  for(var item of data) {
     console.log('item: ', [item.firstname, ...]);
  }
});