Question

检索如下JSON：

"JSON": [
{
  "mySchool": "college",
  "myHome": "apartment",
  "myFavoriteSport": "soccer"
},
{
  "mySchool": "highschool",
  "myHome": "house",
  "myFavoriteSport": "hockey"
},
{
  "mySchool": "college",
  "myHome": "box",
  "myFavoriteSport": "soccer"
},
{
  "mySchool": "elementary",
  "myHome": "tent",
  "myFavoriteSport": "soccer"
}
]

我该如何有条件地对其进行过滤，以便...如果soccer是myFavoriteSport键的值，然后返回包含myFavoriteSport: soccer对的所有对象的数组？我确定我最终会将对象pushing放入数组中，但是我不太了解如何将其分离出来，以便将其分配给变量。

我确定它会涉及某种类型的循环，但这是我第一次使用JSON和这种类型的对象，因此我不太确定如何处理它。

Answer 1

如果要过滤，请使用.filter-只需检查myFavoriteSport属性是否为soccer：

const input = {
  "JSON": [
    {
      "mySchool": "college",
      "myHome": "apartment",
      "myFavoriteSport": "soccer"
    },
    {
      "mySchool": "highschool",
      "myHome": "house",
      "myFavoriteSport": "hockey"
    },
    {
      "mySchool": "college",
      "myHome": "box",
      "myFavoriteSport": "soccer"
    },
    {
      "mySchool": "elementary",
      "myHome": "tent",
      "myFavoriteSport": "soccer"
    }
  ]
};
console.log(
  input.JSON.filter(({ myFavoriteSport }) => myFavoriteSport === 'soccer')
);

还请注意，JSON是一种以字符串格式表示对象的方式。（例如，

const myJSON = '[{"foo":"bar"},{"baz":"buzz"}]';

）。如果您有实际的对象/数组，则它不是JSON格式-只是一个普通对象。最好使用诸如arr或personArr之类的名称。 There's no such thing as a "JSON Object"

Answer 2

使用filter()数组方法很容易实现，有一个单一的解决方案：您可以在回调函数中指定一个条件，最后您将获得一个新的符合条件的数组。

const JSON = [
  {
    "mySchool": "college",
    "myHome": "apartment",
    "myFavoriteSport": "soccer"
  },
  {
    "mySchool": "highschool",
    "myHome": "house",
    "myFavoriteSport": "hockey"
  },
  {
    "mySchool": "college",
    "myHome": "box",
    "myFavoriteSport": "soccer"
  },
  {
    "mySchool": "elementary",
    "myHome": "tent",
    "myFavoriteSport": "soccer"
  }
];

const result = JSON.filter(item => item.myFavoriteSport === 'soccer');
console.log(result);

您还可以使用许多其他的数组迭代方法来获得这样的结果，但是filter非常适合您的需求。

Javascript：根据键的值有条件地过滤JSON？

2 个答案: