Javascript 用对象和重命名属性展平深度嵌套的数组

Question

我再次陷入对以下内容的一些扁平化和重命名中。 我得到了什么：

  test = [
    {
      date: '2020-03-30',
      station: {
        id: 0,
        name: 'some description'
      },
      firstValues: [
        {
          result: 1,
          type: 4,
          max: 18,
          min: 1,
        },
        {
          result: 2,
          type: 5,
          max: 15,
          min: 2,
        }
      ],
      lastValues: [
        {
          result: 1,
          type: 3,
          max: 17,
          min: 1
        },
        {
          result: 2,
          type: 8,
          max: 20,
          min: 2
        }
      ],
      iD: 'xxx3',
      count: 1
    },
    {
    next object with same structure
    }
  ]

我试图达到的目标：

  test = [
    {
      date: '2020-03-30',
      station: 'some description',
      first_E01_result: 1,
      first_E01_type: 4,
      first_E01_max: 18,
      first_E01_min: 1,
      first_E02_result: 2,
      first_E02_type: 5,
      first_E02_max: 15,
      first_E02_min: 2,
      last_E01_result: 1,
      last_E01_type: 3,
      last_E01_max: 17,
      last_E01_min: 1,
      last_E02_result: 2,
      last_E02_type: 8,
      last_E02_max: 20,
      last_E02_min: 2,
      iD: 'xxx3',
      count: 1
    },
    {
    next object with same structure
    }
  ]

我很清楚我的方法不是正确的。 到目前为止，我尝试了不同的方法，但无法正常工作。 我完全再次陷入寻找正确方法的困境，因为我确实遇到了两个主要问题：

如何区分第一个值和最后一个值？ (switch case or if and if else?) 以及如何从站 object 访问名称属性并将其分配给“站”的键

这是我的最后一种方法，它仍然缺少上述问题的正确代码：

  convertTest(input) {
    return input.map(obj => {
      const obj1 = {};
      const obj2 = {};
      for (const prop in obj) {
        if (obj.hasOwnProperty(prop) && Array.isArray(obj[prop])) {
          for (let i = 0; i < obj[prop].length; i++) {
            for (const [key, value] of Object.entries(obj[prop][i])) {
              const name = 'first_EO' + (i + 1).toString() + '_' + key;
              obj2[name] = value;
            }
          }
        } else {
          obj1[prop] = obj[prop];
        }
        const dataconverted = Object.assign({}, obj1, obj2);
        return dataconverted;
      }
    });
  }

Answer 1

您可以对除具有特殊情况的第一级之外的所有其他嵌套对象采用递归方法。

 var data = [{ date: '2020-03-30', station: { id: 0, name: 'some description' }, firstValues: [{ result: 1, type: 4, max: 18, min: 1 }, { result: 2, type: 5, max: 15, min: 2 }], lastValues: [{ result: 1, type: 3, max: 17, min: 1 }, { result: 2, type: 8, max: 20, min: 2 }], iD: 'xxx3', count: 1 }], getPath = object => Object.entries(object).reduce((r, [k, v], i) => { if (v && typeof v === 'object') { r.push(...getPath(v).map(([left, right]) => [(Array.isArray(object)? 'E' + (i + 1).toString().padStart(2, 0): k) + '_' + left, right])); } else { r.push([k, v]); } return r; }, []), result = data.map(o => Object.fromEntries(Object.entries(o).reduce((r, [k, v]) => { if (k === 'station') { r.push([k, v.name]); } else if (v && typeof v === 'object') { if (k.endsWith('Values')) k = k.slice(0, -6); r.push(...getPath(v).map(([left, right]) => [k + '_' + left, right])); } else { r.push([k, v]); } return r }, []))); console.log(result);

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

Answer 2

请试试这个。

 test = test.map((elem) => { elem.firstValues.forEach((child, index) => { for(let key in child){ let v = `first_E${index+1}_${key}` elem[v] = child[key]; } }) elem.lastValues.forEach((child, index) => { for(let key in child){ let v = `last_E${index+1}_${key}` elem[v] = child[key]; } }) elem['station'] = elem.station.name; delete elem.firstValues; delete elem.lastValues; return elem; })

Answer 3

您应该使用 Map 和 Object.keys

 var test = [{"date":"2020-03-30","station":{"id":0,"name":"some description"},"firstValues":[{"result":1,"type":4,"max":18,"min":1},{"result":2,"type":5,"max":15,"min":2}],"lastValues":[{"result":1,"type":3,"max":17,"min":1},{"result":2,"type":8,"max":20,"min":2}],"iD":"xxx3","count":1}] console.log(flatten(test)); function flatten(arr) { return arr.map(el => ModifyObject(el)) } function ModifyObject(el) { const obj = {}; obj.date = el.date; obj.iD = el.iD; obj.count = el.count; obj.station = el.station.name; flattenObjectByProperty(obj, el, 'firstValues') flattenObjectByProperty(obj, el, 'lastValues') return obj; } function flattenObjectByProperty(obj, el, property) { (el[property] || []).map((child, i) => { Object.keys(child).forEach(key => { obj[property + '_E' + i + '_' + key] = child[key] }); }); }

Answer 4

您可以根据您的要求使用Array.prototype.reduce展平

 const test = [ { date: '2020-03-30', station: { id: 0, name: 'some description' }, firstValues: [ { result: 1, type: 4, max: 18, min: 1, }, { result: 2, type: 5, max: 15, min: 2, } ], lastValues: [ { result: 1, type: 3, max: 17, min: 1 }, { result: 2, type: 8, max: 20, min: 2 } ], iD: 'xxx3', count: 1 } ]; const result = test.reduce((acc, curr) => { const { firstValues, lastValues, ...rest } = curr; const modifiedFirstValues = firstValues.reduce((r, c, i) => { Object.entries(c).forEach(([key, value]) => { const modifiedKey = `first_E${i + 1}_${key}`; r[modifiedKey] = value; }); return r; }, Object.create(null)); const modifiedLastValues = lastValues.reduce((r, c, i) => { Object.entries(c).forEach(([key, value]) => { const modifiedKey = `last_E${i + 1}_${key}`; r[modifiedKey] = value; }); return r; }, Object.create(null)); const finalObj = {...rest, ...modifiedFirstValues, ...modifiedLastValues }; acc.push(finalObj); return acc; }, []); console.log(result);