如何根据属性值或属性的存在过滤数组[重复]

Question

我将如何根据其中的特定属性过滤数组？

例如，如果我只想要其中包含 season 属性的对象。

[
  {
    population: 121321313,
    location: 'American city in the East',
  },
  {
    season: 'winter',
    population: 54646546,
    location: 'Canadian city in the East',
  },
  {
    population: 6546467,
    location: 'American city in the West',
  },
  {
    season: 'fall',
    population: 145313,
    location: 'American city in the South',
  },
  {
    population: 12673,
    location: 'Canadian city2 in the East',
  },
  {
    population: 141313,
    location: 'Canadian city in the South',
  },
  {
    season: 'fall',
    population: 1264473,
    location: 'Canadian city4 in the East',
  },
  {
    population: 12673,
    location: 'Canadian city6 in the South',
  },
];

Answer 1

你可以使用 语句 - for..of, for iterate objects 然后找到你的项目并推送到新数组

const list = [
  {
    "population": 121321313,
    "location": "American city in the East"
  },
  {
    "season": "winter",
    "population": 54646546,
    "location": "Canadian city in the East"
  },
  {
    "population": 6546467,
    "location": "American city in the West"
  },
  {
    "season": "fall",
    "population": 145313,
    "location": "American city in the South"
  },
  {
    "population": 12673,
    "location": "Canadian city2 in the East"
  },
  {
    "population": 141313,
    "location": "Canadian city in the South"
  },
  {
    "season": "fall",
    "population": 1264473,
    "location": "Canadian city4 in the East"
  },
  {
    "population": 12673,
    "location": "Canadian city6 in the South"
  }
  
];

let Newarr = [];

for (const item of list) {

  if(Object.hasOwn(item, "season")) {
      Newarr.push(item);
  }
}

console.log(Newarr);

Answer 2

您正在寻找Object#hasOwnProperty。具体来说，您正在寻找 filter 您的数组，仅查找具有 season 属性的项目，您可以像这样完成：

const cities = [
  { "population": 121321313, "location": "American city in the East" },
  { "season": "winter", "population": 54646546, "location": "Canadian city in the East" },
  { "population": 6546467,"location": "American city in the West"},
  { "season": "fall", "population": 145313, "location": "American city in the South" },
  { "population": 12673, "location": "Canadian city2 in the East" },
  { "population": 141313, "location": "Canadian city in the South" },
  { "season": "fall", "population": 1264473, "location": "Canadian city4 in the East" },
  { "population": 12673, "location": "Canadian city6 in the South" }
];

const filteredCities = cities.filter(x => x.hasOwnProperty("season"));

console.dir(filteredCities);

---

您也可以使用更现代的Reflect.has。请参阅Javascript object.hasOwnProperty() vs Reflect.has() 或How do I check if an object has a specific property in JavaScript? 了解更多信息。

const cities = [
  { "population": 121321313, "location": "American city in the East" },
  { "season": "winter", "population": 54646546, "location": "Canadian city in the East" },
  { "population": 6546467,"location": "American city in the West"},
  { "season": "fall", "population": 145313, "location": "American city in the South" },
  { "population": 12673, "location": "Canadian city2 in the East" },
  { "population": 141313, "location": "Canadian city in the South" },
  { "season": "fall", "population": 1264473, "location": "Canadian city4 in the East" },
  { "population": 12673, "location": "Canadian city6 in the South" }
];

const filteredCities = cities.filter(x => Reflect.has(x, "season"));

console.dir(filteredCities);