我需要以下对象数组中具有最后一个索引的唯一对象

Question

[{
    "Screen Size": [{
        "name": "15 inch - 15.9 inch",
        "filter": "200067-200324",
        "isChecked": true
    }]
}, {
    "Type": [{
        "name": "Ultrabook",
        "filter": "200060-200289",
        "isChecked": true,
   
    }, {
        "name": "Notebook",
        "filter": "200060-200290",
        "isChecked": true,
     
    }]
}, {
    "Type": [{
        "name": "Laptop",
        "filter": "200060-200288",
        "isChecked": true,
     
    }, {
        "name": "Ultrabook",
        "filter": "200060-200289",
        "isChecked": true,

    }, {
        "name": "Notebook",
        "filter": "200060-200290",
        "isChecked": true,
 
    }]
}, {
    "Brand": [{
        "name": "HP",
        "filter": "200140-200886",
        "isChecked": true,
    
    }, {
        "name": "Lenovo",
        "filter": "200140-200887",
        "isChecked": true,

    }]
}, {
    "Brand": [{
        "name": "HP",
        "filter": "200140-200886",
        "isChecked": true,

    }, {
        "name": "Lenovo",
        "filter": "200140-200887",
        "isChecked": true,
    }, {
        "name": "Dell",
        "filter": "200140-200888",
        "isChecked": true,

    }]
}]

从上面的对象数组中，我想过滤唯一键，即索引号最大的键。

例如，在品牌中，我想要最后一个，因为它会有一个更高的指数。

我将合并对象的这些数组，因此我只得到一个包含其内部对象的数组

预期输出

[{
    "name": "15 inch - 15.9 inch",
    "filter": "200067-200324",
    "isChecked": true
}, {
    "name": "Notebook",
    "filter": "200060-200290",
    "isChecked": true,
}, {
    "name": "Dell",
    "filter": "200140-200888",
    "isChecked": true,
}]

Answer 1

您可以通过一个reduce()调用来实现这一点，获取第一个(only?)属性在累加器中对结果进行哈希处理，然后遍历值数组以检查更大的filter属性。

​

const
  output = input.reduce((a, o) => {
    let k = Object.keys(o)[0];
    o[k].forEach(e => {
      if ((a[k] ??= { ...e }).filter < e.filter) {
        a[k] = { ...e };
      }
    });
    return a;
  }, {});

console.log(output); // Output is an object with each category as property.
console.log(Object.values(output)); // or Array from Object.values()

.as-console-wrapper { max-height: 100% !important; top: 0; }

<script>
const input = [{ "Screen Size": [{ "name": "15 inch - 15.9 inch", "filter": "200067-200324", "isChecked": true }] }, { "Type": [{ "name": "Ultrabook", "filter": "200060-200289", "isChecked": true, }, { "name": "Notebook", "filter": "200060-200290", "isChecked": true, }] }, { "Type": [{ "name": "Laptop", "filter": "200060-200288", "isChecked": true, }, { "name": "Ultrabook", "filter": "200060-200289", "isChecked": true, }, { "name": "Notebook", "filter": "200060-200290", "isChecked": true, }] }, { "Brand": [{ "name": "HP", "filter": "200140-200886", "isChecked": true, }, { "name": "Lenovo", "filter": "200140-200887", "isChecked": true, }] }, { "Brand": [{ "name": "HP", "filter": "200140-200886", "isChecked": true, }, { "name": "Lenovo", "filter": "200140-200887", "isChecked": true, }, { "name": "Dell", "filter": "200140-200888", "isChecked": true, }] }]
</script>

​

如果您的顶级对象将具有多个属性，则需要迭代每个条目，而不仅仅是检索第一个属性。

const input = [
  {
    "Screen Size": [],
    "Type": [],
    "Brand": []
  }, {
    "Type": [],
    "Brand": []
  }
];

​

const
  output = input.reduce((a, o) => {
    Object.entries(o).forEach(([k, v]) => {
      v.forEach(e => {
        if ((a[k] ??= { ...e }).filter < e.filter) {
          a[k] = { ...e };
        }
      });
    });
    return a;
  }, {});

console.log(output); // Output is an object with each category as property.
console.log(Object.values(output)); // or Array from Object.values()

.as-console-wrapper { max-height: 100% !important; top: 0; }

<script>
const input = [{ "Screen Size": [{ "name": "15 inch - 15.9 inch", "filter": "200067-200324", "isChecked": true }], "Type": [{ "name": "Ultrabook", "filter": "200060-200289", "isChecked": true, }, { "name": "Notebook", "filter": "200060-200290", "isChecked": true, }], "Brand": [{ "name": "HP", "filter": "200140-200886", "isChecked": true, }, { "name": "Lenovo", "filter": "200140-200887", "isChecked": true, }] }, { "Type": [{ "name": "Laptop", "filter": "200060-200288", "isChecked": true, }, { "name": "Ultrabook", "filter": "200060-200289", "isChecked": true, }, { "name": "Notebook", "filter": "200060-200290", "isChecked": true, }], "Brand": [{ "name": "HP", "filter": "200140-200886", "isChecked": true, }, { "name": "Lenovo", "filter": "200140-200887", "isChecked": true, }, { "name": "Dell", "filter": "200140-200888", "isChecked": true, }] }]
</script>

​