如何处理对象数组？ 我有一个包含3个对象的数组，这些对象包含来自数据库的JSON数据

Question

Basically, I have an array of posts that contains 3 objects: posts[{},{},{}]

Each object looks something like this:

1: Object
__v: 0
_id: "5686e17fc64feafd4486f22c"
created_at: "2016-01-01T20:28:47.889Z"
image: "Test"
message: "Test"
title: "Test Post 1"
updated_at: "2016-01-01T20:28:47.889Z"

I'm wondering how I can get an index or something of each object, but also use that for the object's properties.

I was testing earlier with an object of objects, and all I had to do there was: Object.keys(this.props.data).map(this.renderPostTile) . Then I could just use a parameter for renderPostTile(key) .

How can I do something similar when I have an array of objects?

Answer 1

Like this:

 var posts = [ { title: "Test Post 1" }, { title: "Test Post 2" }, { title: "Test Post 3" } ]; posts.map(function(post){ var p = document.createElement("p"), t = document.createTextNode(post.title); p.appendChild(t); document.body.appendChild(p); }); 

Obviously your objects are more complicated, but you get the idea.

Edit:

React-wise, you could do something like this:

var PostListRender = React.createClass({
  render: function() {
    return (
      <ul>
        {this.props.posts.map(function(post){
          return <li>{post.title}</li>;
        })}
      </ul>
    )
  }
});

var posts = [
  {title: "Test Post 1"}, 
  {title: "Test Post 2"}, 
  {title: "Test Post 3"}
];

var el = document.getElementById('post-container');
React.render( < PostListRender posts = {posts} />, el);

Demo

Answer 2

Object.keys returns an Array, that's why you can do .map() on it, which is an Array method. So yeah, you can utilize map on the Array. Literally just call posts.map(myCallback);

You're literally taking something where you converted an Object's keys INTO an Array for the purposes of using an Array method on it and asking "Can I do this to an Array too?" The answer is "well...of course, you just don't have to convert it to anything first...just call the Array's .map method" .

---

You keep saying it says that postData.map isn't a function...but you say your Array is named posts ...so it would be posts.map . If whatever you're working with doesn't have a map method, then it's not an Array (at least in modern browsers). Make sure you're calling it on the Array.