如何过滤数组中的对象？

Question

我想用单个对象检查数组内的条件。let arr = [  {    name: "john",    description: {      height: 5.5,      weight: 54,    },  },  {    name: "mary",    description: {      height: 5.8,      weight: 65,    },  },  {    name: "smith",    description: {      height: 6.1,      weight: 85,    },  },];let obj = {  height: 5.8,  weight: 65,};我想比较数组中的obj，如果它匹配一个，我想得到这个名字。对于ex来说，obj等于结婚。我想打印玛丽。这就是我尝试过的。let result = arr.filter((item) => item.description === obj )console.log(result.name);

Answer 1

您可以使用对象的条目构建一个过滤器，并循环访问所有条目并检查值。然后映射名称。

let array = [{ name: "john", description: { height: 5.5, weight: 54 } }, { name: "mary", description: { height: 5.8, weight: 65 } }, { name: "smith", description: { height: 6.1, weight: 85 } }],

    object = { height: 5.8, weight: 65 },

    filters = Object.entries(object),

    result = array

        .filter(({ description }) => filters.every(([key, value]) => description[key] === value))

        .map(({ name }) => name);

console.log(result);

Answer 2

您必须将所需的键相互比较，而不是比较对象，因为对象相等性基于它们的内存地址是否相同。

let arr = [

  {

    name: "john",

    description: {

      height: 5.5,

      weight: 54

    }

  },

  {

    name: "mary",

    description: {

      height: 5.8,

      weight: 65

    }

  },

  {

    name: "smith",

    description: {

      height: 6.1,

      weight: 85

    }

  }

];

let obj = {

  height: 5.8,

  weight: 65

};

console.log(

  arr.filter(item => item.description.height === obj.height && item.description.weight === obj.weight)

);

Answer 3

一种方法是使用 .Object.keys

var arr = [ { name: "john", description: { height: 5.5, weight: 54, }, }, { name: "mary", description: { height: 5.8, weight: 65, }, }, { name: "smith", description: { height: 6.1, weight: 85, }}];

var obj = { height: 5.8, weight: 65 };

var result = arr.filter(({description})=>Object.keys(description).every(k=>description[k]==obj[k])).map(({name})=>name);

console.log(result);

Answer 4

您可以缩小要过滤的属性范围，如下所示

  let arr = [{

      name: "john",

      description: {

        height: 5.5,

        weight: 54

      }

    },

    {

      name: "mary",

      description: {

        height: 5.8,

        weight: 65

      }

    },

    {

      name: "smith",

      description: {

        height: 6.1,

        weight: 85

      }

    }

  ];

  let obj = {

    height: 5.8,

    weight: 65

  };

  const filtered = arr.filter(({ description }) => description.height === obj.height && description.weight === obj.weight);

  console.log(filtered)

Answer 5

筛选器筛选条件失败的根本原因是由于尝试的对象之间的比较。

对象的比较可以通过使用帮助程序函数来完成。

以下是工作原理：

// array-filter-demo.js

let arr = [

    { name: "john", description: { height: 5.5, weight: 54 } },

    { name: "mary", description: { height: 5.8, weight: 65 } },

    { name: "smith",description: { height: 6.1, weight: 85 } }

  ]

let obj = { height: 5.8, weight: 65 }

// Helper function to compare objects

function matching(a, b) {

   return ( a.height === b.height && a.weight === b.weight)

}

// Call the helper function inside filter

const result = arr.filter(item => (matching(item.description, obj)))

console.log(result)

输出：

$ node array-filter-demo.js 

[ { name: 'mary', description: { height: 5.8, weight: 65 } } ]