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Puvvl
Asked:2020-10-18 19:29:51 +0000 UTC2020-10-18 19:29:51 +0000 UTC

数据搜索和 indexOf() 输出

  • 772

你好，我有这种格式的数据：

[
  {
    "name": "Alexandra Palace",
    "code": "AAP",
    "lat": 51.59793,
    "lon": -0.12023
  },
  {
    "name": "Achanalt",
    "code": "AAT",
    "lat": 57.60958,
    "lon": -4.91386
  },
  {
    "name": "Aberdare",
    "code": "ABA",
    "lat": 51.71506,
    "lon": -3.4431
  }
]

我想用code: ABAwrite:找到元素locations.map((key) => key.code).indexOf('ABA') > -1。true一切正常时的问题。在数据中找到这个后code，我需要显示name这个code（应该显示Aberdare）。告诉我怎么做？

javascript

2 个回答

  1. Best Answer

    不使用indexOf().

    var found = locations.find((loc) => {
    return loc.code === "ABA";
});

var res = found ? found.name : undefined;

    答案 ( name) 将包含在变量中res。"ABA"如果根本找不到带有代码的元素，res则undefined. undefined也将在元素被"ABA"代码找到但它没有字段的情况下name。

    工作示例：

    var locations = [
  {
    "name": "Alexandra Palace",
    "code": "AAP",
    "lat": 51.59793,
    "lon": -0.12023
  },
  {
    "name": "Achanalt",
    "code": "AAT",
    "lat": 57.60958,
    "lon": -4.91386
  },
  {
    "name": "Aberdare",
    "code": "ABA",
    "lat": 51.71506,
    "lon": -3.4431
  }
]

var found = locations.find((loc) => {
    return loc.code === "ABA";
});

var res = found ? found.name : undefined;
console.log(res);

    • 1

  2. 将 map 应用于输出数组中的数组后，只剩下代码字段的值

    const locations = [
  {
    "name": "Alexandra Palace",
    "code": "AAP",
    "lat": 51.59793,
    "lon": -0.12023
  },
  {
    "name": "Achanalt",
    "code": "AAT",
    "lat": 57.60958,
    "lon": -4.91386
  },
  {
    "name": "Aberdare",
    "code": "ABA",
    "lat": 51.71506,
    "lon": -3.4431
  }
];

const m = locations.map((key) => key.code);

console.log(m);

    您可以将 map 替换为例如 filter，其中函数以相同的方式对数组的每个元素执行，返回逻辑运算的结果。filter 创建一个新数组，并将函数返回 true 的源数组的所有元素放入其中：

    const locations = [
  {
    "name": "Alexandra Palace",
    "code": "AAP",
    "lat": 51.59793,
    "lon": -0.12023
  },
  {
    "name": "Achanalt",
    "code": "AAT",
    "lat": 57.60958,
    "lon": -4.91386
  },
  {
    "name": "Aberdare",
    "code": "ABA",
    "lat": 51.71506,
    "lon": -3.4431
  }
];

const res = locations.filter(v => {
  return v.code === "ABA";
})[0];

console.log(res.code);

    • 0

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