javascript - lodash _.filter 返回空数组

Question

我在使用 lodash _.filter 的 Angular.js 中陷入困境。

$scope.test = [
    { name: 'FirstName', items: ["Phone", "Tablet"] },
    { name: 'FirstName', items: ["TV"] },
];
$scope.items = [
    { item: "Phone" },
    { item: "Tablet" }
]
$scope.fined = [];
$scope.fined = _.filter(test, _.matches(items));
console.log(fined)// result []

我预计:

$scope.fined= [{name:'FirstName',items:["Phone","Tablet"]}];

我不知道为什么，但 _.filter 返回空数组:-(

一些想法？

Answer 1

_.matches 的工作方式是传递一个对象，然后在返回的谓词函数中检查该对象的键值对。所以你的案例应该是这样的:

var test = [
    { name: 'FirstName', items: ["Phone", "Tablet"] },
    { name: 'FirstName', items: ["TV"] },
];
var items = { items:  ["Phone", "Tablet"] };

var fined = _.filter(test, _.matches(items));
console.log(fined);

引用文档:

This method supports comparing arrays, booleans, Date objects, numbers, Object objects, regexes, and strings. Objects are compared by their own, not inherited, enumerable properties.

请注意，使用下划线时这不起作用，因为这不会对数组元素进行深度检查。

参见a working example