How to append keys and zero float values to objects in array of objects ? - Javascript

Question

I have an input array of object and a desired/output array

Input Array of object

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"
}
];

I have this as the desired array of object

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"
   }
  ];

What I have to do is that suppose in the first object in the input array of object, only Thickness10Qty and Thickness5Qty, so I have to enter other keys as 0. I want to have equal number of keys in every objects. Similarly for the last object in the input array of object, only Thickness26Qty exists. So we have insert other keys as 0 to have equal number of keys in every objects.

How can I achieve this desired array of object with equal number of keys?

The keys cannot be hard coded, it is coming from a service, the service may return Thickness34Qty/Thickness46Qty instead of Thickness22Qty or Thickness38Qty instead of Thickness18Qty

Post JavaScript as a minimal reproducible example -- specifically the function(s) and/or expression, and/or statements...basically some code that actually does something (or tries to despite errors). — zer00ne
– zer00ne, Commented Apr 18, 2019 at 4:04

Mark · Accepted Answer · 2019-04-18 04:20:14Z

1

You could make a template object that has all the keys set to 0.00 which defines which fields you want, then you can use Object.assign() inside map() to merge this with your existing object.

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)

answered Apr 18, 2019 at 4:20

Mark

92.7k8 gold badges116 silver badges156 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Jack Bashford · Accepted Answer · 2019-04-18 04:21:47Z

1

Make an array of all the keys that should be in an object, then iterate through the array of objects, and add any keys that are missing, with the value 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; }

If the keys are variable (e.g. you want every object to have the same keys):

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; }

edited Apr 18, 2019 at 4:21

answered Apr 18, 2019 at 4:05

Jack Bashford

44.3k11 gold badges56 silver badges84 bronze badges

7 Comments

Scooby Over a year ago

the keys cannot be hard coded, it is coming from a service, the service may return Thickness34Qty instead of Thickness22Qty

Jack Bashford Over a year ago

Then just replace keys with the keys you need, in the format of [keyName].

Scooby Over a year ago

Can you please recheck the solution

Scooby Over a year ago

Can you please modify the fiddle and kindly demonstrate?

vol7ron Over a year ago

nice +1: love that map(Object.keys)

|

vol7ron · Accepted Answer · 2019-04-18 04:39:59Z

This may not set any performance records, but should demonstrate the steps that occur and how it can be slightly optimized. It's important to note that operating on the objects will mutate the objects in the input array, so there is no input/output array as that would require cloning the objects and more work than is required.

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"
    }
  ];
}

stwilz · Accepted Answer · 2019-04-18 08:07:42Z

0

I think @mark-meyer is on the money with this one. I'll just offer a slightly more readable version.

    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,
    }));

answered Apr 18, 2019 at 8:07

stwilz

2,4172 gold badges23 silver badges26 bronze badges

Collectives™ on Stack Overflow

How to append keys and zero float values to objects in array of objects ? - Javascript

4 Answers 4

Comments

7 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

7 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related