Angular2 Typescript如何从对象内部检索数组 [英] Angular2 Typescript how to retrieve an array from inside an object

问题描述

当我执行以下console.log时:

When I do console.log of the following:

console.log(this.categories);

我得到这个结构:

是通过api的json创建的

which was created from this json from the api:

[
  {
  "id":"dff0bb3e-889f-43e6-b955-52cc7203952f",
  "name":"Wood",
  "category_types":[
     {
        "id":"49b31f43-d98d-43c8-9798-088ec6914fe5",
        "name":"Solid"
     },
     {
        "id":"8592716a-ffd5-4e97-ba9e-6a64ba6e48f1",
        "name":"Engineered"
     }
  ]
  },
  {
  "id":"6b2b6914-6c64-4389-a327-be3f08fd066d",
  "name":"Carpet",
  "category_types":[
     {
        "id":"0e2c8473-90fb-4806-a6e7-2389eeb0f9e4",
        "name":"Loop pile"
     },
     {
        "id":"3c762653-4f0d-42d2-a84e-133c7051c95b",
        "name":"Cut pile"
     },
     {
        "id":"0997d4dc-e886-46ef-83b4-d90c4fb72553",
        "name":"Cut \u0026 loop pile"
     }
  ]
  }
]

鉴于我在名为value的字符串变量中具有值'Wood'，如何获取Wood对象的category_types数组?

Given that I have the value 'Wood' in a string variable called value, how do I get hold of the category_types array for the Wood object?

console.log(this.categories[value]);

返回未定义.

推荐答案

您要查找名称为"Wood"的对象，然后获取category_types. Array.prototype.find返回满足提供的测试功能中条件的第一个值.在您的情况下，可能看起来像这样:

You want to find object that has name of 'Wood', then get category_types. Array.prototype.find returns first value that meets the condition in the provided test function. In your case, it could look like this:

this.categories.find(value => value.name === 'Wood').category_types

这篇关于Angular2 Typescript如何从对象内部检索数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！