如何将键和零浮点值附加到对象数组中的对象？ -Javascript

Question

我有一个对象的输入数组和一个期望/输出数组

对象的输入数组

var input = [{
"Grade": "AU27",
"Thickness10Qty": "7.00",
"Thickness5Qty": "19.20",
"TotalQty": "26.20"
},
{
"Grade": "FE500D",
"Thickness10Qty": "143.00",
"Thickness12Qty": "69.00",
"Thickness8Qty": "30.00",
"TotalQty": "242.00"
}, 
{
"Grade": "GE500D",
"Thickness18Qty": "90.00",
"Thickness22Qty": "40.00",
"TotalQty": "130.00"
}, 
{
"Grade": "HE500D",
"Thickness26Qty": "70.00",
"TotalQty": "70.00"
}
];

我将此作为所需的对象数组

var output = [{
 "Grade": "AU27",
 "Thickness10Qty": "7.00",
 "Thickness5Qty": "19.20",
 "Thickness12Qty": "0.00",
 "Thickness8Qty": "0.00",
 "Thickness18Qty": "0.00",
 "Thickness22Qty": "0.00",
 "Thickness26Qty": "0.00",
 "TotalQty": "26.20"
 },
 {
  "Grade": "FE500D",
  "Thickness10Qty": "143.00",
  "Thickness12Qty": "69.00",
  "Thickness8Qty": "30.00",
  "Thickness5Qty": "0.00",
  "Thickness18Qty": "0.00",
  "Thickness22Qty": "0.00",
  "Thickness26Qty": "0.00",
  "TotalQty": "242.00"
 }, 
 {
  "Grade": "GE500D",
  "Thickness18Qty": "90.00",
  "Thickness22Qty": "40.00",
  "Thickness10Qty": "0.00",
  "Thickness12Qty": "0.00",
  "Thickness8Qty": "0.00",
  "Thickness5Qty": "0.00",
  "Thickness26Qty": "0.00",
  "TotalQty": "130.00"
  }, 
  {
   "Grade": "HE500D",
   "Thickness26Qty": "70.00",
   "Thickness18Qty": "0.00",
   "Thickness22Qty": "0.00",
   "Thickness10Qty": "0.00",
   "Thickness12Qty": "0.00",
   "Thickness8Qty": "0.00",
   "Thickness5Qty": "0.00",
    "TotalQty": "70.00"
   }
  ];

我要做的是假设在对象输入数组的第一个对象中，只有Thickness10Qty和Thickness5Qty，因此我必须将其他键输入为0。我希望每个对象中的键数相等。类似地，对于对象输入数组中的最后一个对象，仅存在Thickness26Qty。因此，我们将其他键插入为0，以使每个对象中的键数量相等。

如何用相同数量的键实现所需的对象数组？

密钥不能被硬编码，它来自服务，服务可能返回Thickness34Qty / Thickness46Qty而不是Thickness22Qty或Thickness38Qty而不是Thickness18Qty

Answer 1

对所有应包含在对象中的键进行数组排列，然后遍历对象数组，并添加所有缺少的键，其值为0.00：

var input = [{
    "Grade": "AU27",
    "Thickness10Qty": "7.00",
    "Thickness5Qty": "19.20",
    "TotalQty": "26.20"
  },
  {
    "Grade": "FE500D",
    "Thickness10Qty": "143.00",
    "Thickness12Qty": "69.00",
    "Thickness8Qty": "30.00",
    "TotalQty": "242.00"
  },
  {
    "Grade": "GE500D",
    "Thickness18Qty": "90.00",
    "Thickness22Qty": "40.00",
    "TotalQty": "130.00"
  },
  {
    "Grade": "HE500D",
    "Thickness26Qty": "70.00",
    "TotalQty": "70.00"
  }
];

var keys = ["Grade", "TotalQty", "Thickness5Qty", "Thickness8Qty", "Thickness10Qty", "Thickness12Qty", "Thickness18Qty", "Thickness22Qty", "Thickness26Qty"];

var output = input.map(obj => {
  keys.forEach(key => obj[key] ? key : obj[key] = "0.00");
  return obj;
});

console.log(output);

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

如果键是可变的（例如，您希望每个对象都具有相同的键）：

var input = [{
    "Grade": "AU27",
    "Thickness10Qty": "7.00",
    "Thickness5Qty": "19.20",
    "TotalQty": "26.20"
  },
  {
    "Grade": "FE500D",
    "Thickness10Qty": "143.00",
    "Thickness12Qty": "69.00",
    "Thickness8Qty": "30.00",
    "TotalQty": "242.00"
  },
  {
    "Grade": "GE500D",
    "Thickness18Qty": "90.00",
    "Thickness22Qty": "40.00",
    "TotalQty": "130.00"
  },
  {
    "Grade": "HE500D",
    "Thickness26Qty": "70.00",
    "TotalQty": "70.00"
  }
];

var keys = [...new Set(input.map(Object.keys).reduce((acc, curr) => acc.concat(curr)))];

var output = input.map(obj => {
  keys.forEach(key => obj[key] ? key : obj[key] = "0.00");
  return obj;
});

console.log(output);

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

Answer 2

您可以创建一个模板对象，该模板对象的所有键均设置为0.00，该键定义了所需的字段，然后可以在Object.assign()内使用map()将其与现有对象合并。

var input = [{"Grade": "AU27","Thickness10Qty": "7.00","Thickness5Qty": "19.20","TotalQty": "26.20"},{"Grade": "FE500D","Thickness10Qty": "143.00","Thickness12Qty": "69.00","Thickness8Qty": "30.00","TotalQty": "242.00"}, {"Grade": "GE500D","Thickness18Qty": "90.00","Thickness22Qty": "40.00","TotalQty": "130.00"}, {"Grade": "HE500D","Thickness26Qty": "70.00","TotalQty": "70.00"}];

// make template of all keys
let template  = input.reduce((obj, item) => (Object.keys(item).forEach(k => obj[k] = '0.00'), obj), {})

// apply to items:
let newArray = input.map(item => Object.assign({}, template, item))

console.log(newArray)

Answer 3

这可能不会设置任何性能记录，但是应该演示发生的步骤以及如何对其进行优化。重要的是要注意，对对象进行操作将使 input 数组中的对象发生变异，因此没有输入/输出数组，因为这将需要克隆对象，并且工作量超出所需。

let array = getData()
normalizeData(array)
console.log('output:', array)

function normalizeData(array) {
  let stored_keys = {}
  
  array.forEach((obj, ndx, arr) => {
    let new_keys = []

    // create keys found in other objects
    Object.keys(stored_keys).forEach(key => {
      if (!(key in obj))
        obj[key] = "0.00"
    })

    // detect new keys
    Object.keys(obj).forEach(key => {
      if (!stored_keys[key]) {
        stored_keys[key] = true // track key
        new_keys.push(key)      // track new keys to apply to previous objects
      }
    })

    // add any new keys to previous objects
    if (new_keys.length)
      for (var i = 0, n = ndx; i < n; i++) {
        let prev_obj = arr[i];
        new_keys.forEach(key => prev_obj[key] = "0.00")
      }

  })
}


function getData() {
  return [{
      "Grade": "AU27",
      "Thickness10Qty": "7.00",
      "Thickness5Qty": "19.20",
      "TotalQty": "26.20"
    },
    {
      "Grade": "FE500D",
      "Thickness10Qty": "143.00",
      "Thickness12Qty": "69.00",
      "Thickness8Qty": "30.00",
      "TotalQty": "242.00"
    },
    {
      "Grade": "GE500D",
      "Thickness18Qty": "90.00",
      "Thickness22Qty": "40.00",
      "TotalQty": "130.00"
    },
    {
      "Grade": "HE500D",
      "Thickness26Qty": "70.00",
      "TotalQty": "70.00"
    }
  ];
}

Answer 4

我认为@ mark-meyer与此有关。我将提供一个更具可读性的版本。

    const baseObject = {
      "Thickness10Qty": "0.00",
      "Thickness5Qty": "0.00",
      "Thickness12Qty": "0.00",
      "Thickness8Qty": "0.00",
      "Thickness18Qty": "0.00",
      "Thickness22Qty": "0.00",
      "Thickness26Qty": "0.00",
      "TotalQty": "0.00"
    };

    const addMissingvalues = arr => arr.map(obj => ({
      ...baseObject,
      ...obj,
    }));