Javascript - Compare two array objects and append values

Question

How to compare two array objects and append first array object on match criteria key with second ? Pls suggest.

For example, in the below data, I need to compare vale_data service key with sli_data service key and if it matches, then append sli_data vol_sli key value to vale_data.

var vale_data = [
          {service: "allocateorder", vol_slo: "10000"},
          {service: "cancelorder", vol_slo: "10000"},
          {service: "adviceorder", vol_slo: "10000"}]

var sli_data = [
          {service: "allocateorder", vol_sli: "0.9484949"},
          {service: "cancelorder", vol_sli: "0.242322"}]

I have tried like below, but it didn't worked.

var vale_data = [
          {service: "allocateorder", vol_slo: "10000"},
          {service: "cancelorder", vol_slo: "10000"},
          {service: "adviceorder", vol_slo: "10000"}]

var sli_data = [
          {service: "allocateorder", vol_sli: "0.9484949"},
          {service: "cancelorder", vol_sli: "0.242322"}]

for (i=0; i<Object.keys(vale_data).length; i++) {
  for (j=0; j<Object.keys(sli_data).length; j++) {
      if (Object.values(vale_data)[i]['service'] == Object.values(sli_data)[i]['service']) {
          vale_data.map(item => {item.vol_sli = Object.values(sli_data)[j]['vol_sli'] })
      }
  }
}

Expected output:

vale_data = [
 {service: "allocateorder", vol_slo: "10000", vol_sli: "0.9484949"},
 {service: "cancelorder", vol_slo: "10000", vol_sli: "0.242322"},
 {service: "adviceorder", vol_slo: "10000", vol_sli: ""} ]

Actual output:

error: Uncaught TypeError: Cannot read property 'service' of undefined

Dhananjai Pai · Accepted Answer · 2019-10-11 21:42:17Z

2

You can try this, by creating an object as a map and then using that to get the output array. Uses the Javascript MAP to store the results

var vale_data = [
          {service: "allocateorder", vol_slo: "10000"},
          {service: "cancelorder", vol_slo: "10000"},
          {service: "adviceorder", vol_slo: "10000"}]

var sli_data = [
          {service: "allocateorder", vol_sli: "0.9484949"},
          {service: "cancelorder", vol_sli: "0.242322"}]
var sli_dataMap = new Map(sli_data.map(({service,vol_sli}) => ([service,vol_sli])));
 
vale_data = vale_data.map(obj => ({...obj,vol_sli:sli_dataMap.get(obj.service) || ''}));

console.log(vale_data);

edited Oct 11, 2019 at 21:42

answered Oct 11, 2019 at 21:32

Dhananjai Pai

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1 Comment

Dhananjai Pai Over a year ago

updated it to Map to make it more readable and reduce the "cognitive complexity"

Ilan Schemoul · Accepted Answer · 2019-10-11 21:38:07Z

0

Iterate through each array and if one sli.service is the same as one vale.service add a vol_sli field equal to sli.vol_sli to this vale.

   vale_data.forEach(function (vale) {
        sli_data.forEach(function (sli) {
            if (sli.service === vale.service) {
                vale.vol_sli = sli.vol_sli;
            }
        })
    });

edited Oct 11, 2019 at 21:38

answered Oct 11, 2019 at 21:36

Ilan Schemoul

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4 Comments

Dhananjai Pai Over a year ago

the complexity is O(n2); you can make it more optimal

Ilan Schemoul Over a year ago

I don't want to, what seems to be an not-so-experimented developers, make him copy-paste complex ES6 (not even IE11 compatible) code with Map and with rest syntax for possible optimization. Readibility and maintenability > performances in 99% of cases.

Dhananjai Pai Over a year ago

you cannot attribute not using a language feature to readability and maintainability!

Ilan Schemoul Over a year ago

Yes I can. There an infinity way of doing a same thing in programming languages, in most cases using a well known feature (forEach) simple to read and understand for you and other devs is the best way to go. In other cases think about optimization.

vijay kumar · Accepted Answer · 2019-10-11 21:38:40Z

0

var vale_data = [
          {service: "allocateorder", vol_slo: "10000"},
          {service: "cancelorder", vol_slo: "10000"},
          {service: "adviceorder", vol_slo: "10000"}]

var sli_data = [
          {service: "allocateorder", vol_sli: "0.9484949"},
          {service: "cancelorder", vol_sli: "0.242322"}]

   var result = vale_data.map(vale_data_value => {
        const check_sli_data = sli_data.find(sli_data_value => sli_data_value.service === vale_data_value.service );
        if(check_sli_data){
          vale_data_value.vol_sli = check_sli_data.vol_sli
        }
        return vale_data_value;
   });

   console.log(result)

answered Oct 11, 2019 at 21:38

vijay kumar

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1 Comment

Dhananjai Pai Over a year ago

the complexity is O(n2); you can make it more optimal

Manjiri K · Accepted Answer · 2019-10-11 21:38:53Z

0

var vale_data = [
    {service: "allocateorder", vol_slo: "10000"},
    {service: "cancelorder", vol_slo: "10000"},
    {service: "adviceorder", vol_slo: "10000"}];

var sli_data = [
    {service: "allocateorder", vol_sli: "0.9484949"},
    {service: "cancelorder", vol_sli: "0.242322"}];


vale_data.map(vale_record => {
    let rec_found = sli_data.find(sli_record => sli_record.service === vale_record.service);
    if(rec_found) {
    vale_record['vol_sli'] = rec_found['vol_sli'];
    }
    else {
    vale_record['vol_sli'] = ''
    } 
    return vale_record;
});

console.log(vale_data);

answered Oct 11, 2019 at 21:38

Manjiri K

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Comments

J. Pichardo · Accepted Answer · 2019-10-11 21:40:04Z

0

One of the possible ways of accomplishing this is using map and find the following way:

var vale_data = [{
    service: "allocateorder",
    vol_slo: "10000"
  },
  {
    service: "cancelorder",
    vol_slo: "10000"
  },
  {
    service: "adviceorder",
    vol_slo: "10000"
  }
];

var sli_data = [{
    service: "allocateorder",
    vol_sli: "0.9484949"
  },
  {
    service: "cancelorder",
    vol_sli: "0.242322"
  }
];

var result = vale_data.map(element => {

  let sli = sli_data.find(service => service["service"] === element["service"]) || 
    { vol_sli: "" };

  return { ...element,
    ...sli
  };

});

console.log(result);

answered Oct 11, 2019 at 21:40

J. Pichardo

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Comments

Soc · Accepted Answer · 2019-10-11 22:07:47Z

0

Slight variation on some of the other answers:

Combine all values into a single array,
reduce the array into a Map

const vale_data = [
  {service: "allocateorder", vol_slo: "10000"},
  {service: "cancelorder", vol_slo: "10000"},
  {service: "adviceorder", vol_slo: "10000"},
]

const sli_data = [
  {service: "allocateorder", vol_sli: "0.9484949"},
  {service: "cancelorder", vol_sli: "0.242322"},
]

const mergedData = [...vale_data, ...sli_data].reduce((map, item) => {
  const existing = map.get(item.service) || { vol_slo: "", vol_sli: "" };
  map.set(item.service, {
    ...existing,
    ...item,
  })
  return map;
}, new Map());

console.log(Array.from(mergedData.values()));

answered Oct 11, 2019 at 22:07

Soc

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