当我有嵌套对象时，我如何使用过滤器?

Consider this example. I am using Lodash

考虑一下这个例子。我用Lodash

 'data': [
        {
            'category': {
                'uri': '/categories/0b092e7c-4d2c-4eba-8c4e-80937c9e483d',
                'parent': 'Food',
                'name': 'Costco'
            },
            'amount': '15.0',
            'debit': true
        },
        {
            'category': {
                'uri': '/categories/d6c10cd2-e285-4829-ad8d-c1dc1fdeea2e',
                'parent': 'Food',
                'name': 'India Bazaar'
            },
            'amount': '10.0',
            'debit': true
        },
        {
            'category': {
                'uri': '/categories/d6c10cd2-e285-4829-ad8d-c1dc1fdeea2e',
                'parent': 'Food',
                'name': 'Sprouts'
            },
            'amount': '11.1',
            'debit': true
        },

When I do

当我做

_.filter(summary.data, {'debit': true})

I get all the objects back.

我把所有的东西都拿回来。

what I want?

我想要的吗?

I want all the objects where category.parent == 'Food', how can I do that?

我想要所有类别的对象。父母=“食物”，我怎么做呢?

I tried

我试着

_.filter(summary.data, {'category.parent': 'Food'})

and got

并得到了

[]

5 个解决方案

#1

_.filter(summary.data, function(item){
  return item.category.parent === 'Food';
});

#2

121

lodash allows nested object definitions:

lodash允许嵌套对象定义:

_.filter(summary.data, {category: {parent: 'Food'}});

As of v3.7.0, lodash also allows specifying object keys in strings:

在v3.7.0中，lodash还允许在字符串中指定对象键:

_.filter(summary.data, ['category.parent', 'Food']);

Example code in JSFiddle: https://jsfiddle.net/6qLze9ub/

js小提琴中的示例代码:https://jsfiddle.net/6qLze9ub/

lodash also supports nesting with arrays; if you want to filter on one of the array items (for example, if category is an array):

lodash还支持数组嵌套;如果您想要筛选其中一个数组项(例如，如果类别是数组):

_.filter(summary.data, {category: [{parent: 'Food'}] });

If you really need some custom comparison, that's when to pass a function:

如果你真的需要一些自定义比较，那就是传递函数的时候了:

_.filter(summary.data, function(item) {
  return _.includes(otherArray, item.category.parent);
});

#3

beginning from v3.7.0 you can do it in this way:

从v3.7.0开始，您可以这样做:

_.filter(summary.data, 'category.parent', 'Food')

#4

_.where(summary.data, {category: {parent: 'Food'}});

Should do the trick too

你也应该这样做吗?

#5

In lodash 4.x, you need to do:

lodash 4。x，你需要做:

_.filter(summary.data, ['category.parent', 'Food'])

(note the array wrapping around the second argument).

(注意围绕第二个参数的数组)。

This is equivalent to calling:

这相当于打电话:

_.filter(summary.data, _.matchesProperty('category.parent', 'Food'))

Here are the docs for _.matchesProperty:

这里是_.matchesProperty的文档:

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

#1

_.filter(summary.data, function(item){
  return item.category.parent === 'Food';
});

#2

121