node.js 如何循环遍历 JSON 对象数组？
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How can I loop through an array of JSON objects?
提问by Chris Paterson
I have JSON data that I need to loop through. The data is in a file titled "people.json" that is structured as listed below:
我有需要循环的 JSON 数据。数据位于名为“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"}, ...]
I want to read each object in this file and save it (I'm using Mongoose). Here is what I have so far:
我想读取这个文件中的每个对象并保存它（我使用的是猫鼬）。这是我到目前为止所拥有的：
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) {});
}
});
I'm unable to get this to work though. What am I doing wrong?
不过，我无法让它发挥作用。我究竟做错了什么？
回答by Ibrahim
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) {});
}
});
回答by hedzr
ES6 for..ofcan do that too.
ES6for..of也可以做到这一点。
fs.readFile('./people.json', 'utf8', function (err,data) {
for(var item of data) {
console.log('item: ', [item.firstname, ...]);
}
});
