javascript Lodash：嵌套对象时如何使用过滤器？
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Lodash: how do I use filter when I have nested Object?
提问by daydreamer
Consider this example. I am using Lodash
考虑这个例子。我正在使用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.
我拿回了所有的物品。
what I want?
我想要的是？
I want all the objects where category.parent == 'Food', how can I do that?
我想要所有对象 where category.parent == 'Food'，我该怎么做？
I tried
我试过
_.filter(summary.data, {'category.parent': 'Food'})
and got
并得到
[]
采纳答案by idbehold
_.filter(summary.data, function(item){
return item.category.parent === 'Food';
});
回答by Akrikos
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:
从 v3.7.0 开始，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/
JSFiddle 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；如果要过滤数组项之一（例如，如果 category 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：
_.filter(summary.data, function(item) {
return _.includes(otherArray, item.category.parent);
});
回答by evilive
beginning from v3.7.0you can do it in this way:
从v3.7.0你开始，你可以这样做：
_.filter(summary.data, 'category.parent', 'Food')
回答by iamyojimbo
In lodash 4.x, you need to do:
在 lodash 4.x 中，您需要执行以下操作：
_.filter(summary.data, ['category.parent', 'Food'])
(note the array wrapping around the second argument).
（注意环绕第二个参数的数组）。
This is equivalent to calling:
这相当于调用：
_.filter(summary.data, _.matchesProperty('category.parent', 'Food'))
Here are the docs for _.matchesProperty:
// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']
回答by Denis
_.where(summary.data, {category: {parent: 'Food'}});
Should do the trick too
也应该这样做
