使用下划线遍历数组或 object

Question

为什么标题 return 为空！！ , 有什么混淆的地方吗 !

这是我的代码

_.each(collection.models, function(element, index, list){
          console.log(JSON.stringify(element)); //{"title":"Dipped Bunny Blossom","id":49,"created_at":"2015-03-24T10:16:17Z","updated_at":"2015-03-24T13:56:12Z","type":"simple","status":"publish","downloadable":false,"virtual":false,"permalink":"http://beta-it.com/ticarttest/shop/dipped-bunny-blossom/","sku":"","price":"50.00","regular_price":"50.00","sale_price":null,"price_html":"<span class=\"amount\">&#36;50.00</span>","taxable":false,"tax_status":"taxable","tax_class":"","managing_stock":false,"stock_quantity":0,"in_stock":true,"backorders_allowed":false,"backordered":false,"sold_individually":false,"purchaseable":true,"featured":true,"visible":true,"catalog_visibility":"visible","on_sale":false,"weight":"1.00","dimensions":{"length":"50","width":"50","height":"50","unit":"cm"},"shipping_required":true,"shipping_taxable":true,"shipping_class":"","shipping_class_id":null,"description":"","short_description":"","reviews_allowed":true,"average_rating":"4.50","rating_count":2,"related_ids":[34,43,45,47,120],"upsell_ids":[],"cross_sell_ids":[],"parent_id":0,"categories":["BIRTHDAY","BUSINESS GIFTS","DIPPED FRUIT"],"tags":[],"images":[{"id":50,"created_at":"2015-03-03T10:16:10Z","updated_at":"2015-03-03T10:16:10Z","src":"http://beta-it.com/ticarttest/wp-content/uploads/2015/03/Dipped-Bunny-Blossom.jpg","title":"Dipped-Bunny-Blossom","alt":"","position":0}],"featured_src":"http://beta-it.com/ticarttest/wp-content/uploads/2015/03/Dipped-Bunny-Blossom.jpg","attributes":[],"downloads":[],"download_limit":0,"download_expiry":0,"download_type":"","purchase_note":"","total_sales":1,"variations":[],"parent":[]}
         console.log(element.id); // return 49 ok
         console.log(element.title); //return null !!!!

        // We are looping through the returned models from the remote REST API
        // Implement your custom logic here
    });

Answer 1

对于 backbone 集合，您的代码应该更像这样：

collection.each(function(model) {
    console.log(model.attributes);
    console.log(model.id);
    console.log(model.get('title'));
});

backbone 模型中的大多数属性必须使用 get method. id is a special case 访问，可以通过 get 或直接 id 属性访问。根据文档：

If you set the id in the attributes hash, it will be copied onto the model as a direct property.

使用下划线遍历数组或 object

Iterate over an array or object with underscore

properties

backbone.js

underscore.js