Question

我有一个对象，需要根据特定的键将其转换为数据数组。

这是我的原始物：

{
  "centerID": "6",
  "marketID": "1",
  "invoiceGroupID": "4",
  "blocks": [
    {
      "name": "Monday-Friday 11:00AM-3:00PM",
      "isChecked": true
    },
    {
      "name": "Monday-Friday 7:00AM-11:00AM",
      "isChecked": false
    },
    {
      "name": "Saturday-Sunday 2:00PM-8:00PM",
      "isChecked": true
    }
  ],
  "bankedHoursYN": "N"
}

当前，我使用filter仅通过blocks向我提供isChecked = true，其中_.filter(this.mappingForm.get('blocks').value, { isChecked: true })。

这样的结果使我有了：

{
  "centerID": "6",
  "marketID": "1",
  "invoiceGroupID": "4",
  "blocks": [
    {
      "name": "Monday-Friday 11:00AM-3:00PM",
      "isChecked": true
    },
    {
      "name": "Saturday-Sunday 2:00PM-8:00PM",
      "isChecked": true
    }
  ],
  "bankedHoursYN": "N"
}

这很好，给我留下了两个对象的数组。

我的最终结果是只拥有一个name值的数组。

预期输出：

{
  "centerID": "6",
  "marketID": "1",
  "invoiceGroupID": "4",
  "blocks": ['Monday-Friday 11:00AM-3:00PM','Saturday-Sunday 2:00PM-8:00PM'],
  "bankedHoursYN": "N"
}

lodash是否有内置的方式来处理此问题？

Answer 1

您可以将_.filter()和_.map()链接起来，用blocks来获得isChecked: true的名称：

const data = { "centerID": "6", "marketID": "1", "invoiceGroupID": "4", "blocks": [ { "name": "Monday-Friday 11:00AM-3:00PM", "isChecked": true }, { "name": "Monday-Friday 7:00AM-11:00AM", "isChecked": false }, { "name": "Saturday-Sunday 2:00PM-8:00PM", "isChecked":true } ], "bankedHoursYN": "N" };

data.blocks = _(data.blocks)
  .filter('isChecked')
  .map('name')
  .value();
  
console.log(data);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

Answer 2

lodash是否有内置的方式来处理此问题？

我不知道，但是Javascript有。

使用Array.prototype.filter()并链接Array.prototype.map()：

let obj = {
  "centerID": "6",
  "marketID": "1",
  "invoiceGroupID": "4",
  "blocks": [
    {
      "name": "Monday-Friday 11:00AM-3:00PM",
      "isChecked": true
    },
    {
      "name": "Monday-Friday 7:00AM-11:00AM",
      "isChecked": false
    },
    {
      "name": "Saturday-Sunday 2:00PM-8:00PM",
      "isChecked": true
    }
  ],
  "bankedHoursYN": "N"
}

obj.blocks = obj.blocks.filter(i=>i.isChecked).map(i=>i.name)

console.log(obj)

如果您需要使用ES5：

obj.blocks = obj.blocks
  .filter(function(i) { return i.isChecked })
  .map(function(i) { return i.name });

Answer 3

过滤blocks后，可以使用map和concat来加入name对象的block。

var data = { "centerID": "6", "marketID": "1", "invoiceGroupID": "4", "blocks": [ { "name": "Monday-Friday 11:00AM-3:00PM", "isChecked": true }, { "name": "Monday-Friday 7:00AM-11:00AM", "isChecked": false }, { "name": "Saturday-Sunday 2:00PM-8:00PM", "isChecked":true } ], "bankedHoursYN": "N" };
data.blocks = _.chain(data.blocks).filter({ isChecked: true }).map(({name}) => name).concat().value();
console.log(data);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

Answer 4

如果您正在搜索用于执行map和filter的内置功能，那么您始终可以将map和filter操作合并到一个{ {1}}（无论是在reduce还是在简单的lodash中）都只能将数组迭代一次。

因此，结构将为：

vanilla JS

因此，在您的情况下： <Array>.reduce((res, each) => (<filter condition> && res.push(<mapped data>), res), [])

obj.blocks.reduce((r, b) => (b.isChecked && r.push(b.name), r), [])

但是，我建议您不要变异并制作原始对象的副本，并覆盖副本上的var obj = { "centerID": "6", "marketID": "1", "invoiceGroupID": "4", "blocks": [ { "name": "Monday-Friday 11:00AM-3:00PM", "isChecked": true }, { "name": "Monday-Friday 7:00AM-11:00AM", "isChecked": false }, { "name": "Saturday-Sunday 2:00PM-8:00PM", "isChecked": true } ], "bankedHoursYN": "N" }; obj.blocks = obj.blocks.reduce((r, b) => (b.isChecked && r.push(b.name), r), []); console.log(obj)以使其成为新的输出。

Answer 5

var data.blocks = .map（ .filter（data.blocks，function（o）{return o.isChecked === true;}），'name'）;

使用lodash通过属性名称从对象创建数组

5 个答案: