Get duplicated values from an array by checking with two element

Question

If My array have this below data

let array = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
        { name: "Suresh", SalseVersion: 12, MarketingCode: 13 },
        { name: "Siva", SalseVersion: 10, MarketingCode: 14 },
        { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 },...]

Then I am expecting this below result

[{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
 { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }]

If My array have this below data

let array = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
        { name: "Suresh", SalseVersion: 12, MarketingCode: 14},
        { name: "Siva", SalseVersion: 12, MarketingCode: 14 },
        { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 },...]

Then I am expecting this below result.

        [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
        { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }
        { name: "Suresh", SalseVersion: 12, MarketingCode: 14},
        { name: "Siva", SalseVersion: 12, MarketingCode: 14 }]

I have tried this way : Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

let arr = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
        { name: "Suresh", SalseVersion: 12, MarketingCode: 13 },
        { name: "Siva", SalseVersion: 10, MarketingCode: 14 },
        { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }]


var sorted_arr = arr.slice().sort();
var results = [];
for (var i = 0; i < sorted_arr.length - 1; i++) {
    if (sorted_arr[i + 1].SalesVersion == sorted_arr[i].SalesVersion && sorted_arr[i + 1].MarketingCode == sorted_arr[i].MarketingCode) {
        results.push(sorted_arr[i]);
    }
}

console.log(results);

But unable to get the duplicated values. Could you please resolve this?

Note: Please mind it should be work as well if the SalseVersion and MarketingCode value is string/number/Boolean.

because I have tried some of the below answers and i am getting this below error.

Eddie · Answer 1 · 2018-05-16T06:28:40.937

You can use reduce

The first reduce will group the values using the concatenated values of SalseVersion and MarketingCode.

The second reduce will check if the group has more than 1 element. If there is concat the values into 1 array.

let array = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },{ name: "Suresh", SalseVersion: 12, MarketingCode: 14},{ name: "Siva", SalseVersion: 12, MarketingCode: 14 },{ name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }];

let result = Object.values(array.reduce((c, v) => {
  let k = v.SalseVersion + '-' + v.MarketingCode;
  c[k] = c[k] || [];
  c[k].push(v);
  return c;
}, {})).reduce((c, v) => v.length > 1 ? c.concat(v) : c, []);

console.log( result );

CertainPerformance · Accepted Answer · 2018-05-16T06:22:45.763

2

It looks like you're trying to find elements for which there exists at least one other element in the array with similar properties. You can use .filter for this, followed by sort:

const dupesFromArr = array => {
  const filteredArr = array.filter(({ name, SalseVersion, MarketingCode }, i, arr) => (
    arr.find((item, findI) => (
      findI !== i &&
      SalseVersion === item.SalseVersion &&
      MarketingCode === item.MarketingCode
    ))
  ));
  return filteredArr.sort((a, b) =>
    String(a.SalseVersion).localeCompare(String(b.SalseVersion), 'kn') ||
    String(a.MarketingCode).localeCompare(String(b.MarketingCode), 'kn')
  );
};

console.log(dupesFromArr([{name:"Ramesh",SalseVersion:10,MarketingCode:11},{name:"Suresh",SalseVersion:12,MarketingCode:13},{name:"Siva",SalseVersion:10,MarketingCode:14},{name:"Sakthi",SalseVersion:10,MarketingCode:11}]))
console.log(dupesFromArr([{name:"Ramesh",SalseVersion:10,MarketingCode:11},{name:"Suresh",SalseVersion:12,MarketingCode:14},{name:"Siva",SalseVersion:12,MarketingCode:14},{name:"Sakthi",SalseVersion:10,MarketingCode:11}]))

edited May 16 '18 at 06:22

answered May 16 '18 at 06:01

CertainPerformance

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I am getting an error in `filteredArr.sort((a, b) => b.SalesVersion - a.SalesVersion || b.MarketingCode - a.MarketingCode);` *the left-hand side of an assignment must be variable any int or enum* because the `SalesVersion` property type is string. – Ramesh Rajendran May 16 '18 at 06:06
yes I have copied it correctly. But typescript does not allow that – Ramesh Rajendran May 16 '18 at 06:11
Your editor is telling you that MarketingCode properties are `string`, but the code you posted shows that they're integers. Something doesn't add up here. – CertainPerformance May 16 '18 at 06:15
1

@RameshRajendran, you can force result using `+` operator. Something like this: `return filteredArr.sort((a, b) => +a.SalseVersion - (+b.SalseVersion) || +a.MarketingCode - (+b.MarketingCode));` – Mihai Alexandru-Ionut May 16 '18 at 06:19
@Mihai If `MarketingCode` were a `string`, then `+Marketing` would be `NaN`. – tony19 May 16 '18 at 06:21
@RameshRajendran Edited to show a solution that converts the items to strings and uses `localeCompare` – CertainPerformance May 16 '18 at 06:23
`.1` That make sense :) – Ramesh Rajendran May 16 '18 at 06:25

Nikhil Aggarwal · Answer 3 · 2018-05-16T06:06:25.760

You can update your code to following

let arr = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 },
    { name: "Suresh", SalseVersion: 12, MarketingCode: 14},
    { name: "Siva", SalseVersion: 12, MarketingCode: 14 },
    { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 },
    { name: "OP", SalseVersion: 10, MarketingCode: 11 }]

// You need to write the custom sort function
var sorted_arr = arr.slice().sort((a,b) => {
     if(a.SalseVersion === b.SalseVersion) {
          return a.MarketingCode- b.MarketingCode;
      }
      return a.SalseVersion - b.SalseVersion;
});
var results = [];
for (var i = 0; i < sorted_arr.length - 1; i++) {
    if (sorted_arr[i + 1].SalesVersion == sorted_arr[i].SalesVersion && sorted_arr[i + 1].MarketingCode == sorted_arr[i].MarketingCode) {
        /* push both the elements in case of match with only exception 
         * being if it has been pushed previously where there are more than 2 matches */
       if (i >= 1 && sorted_arr[i - 1].SalesVersion == sorted_arr[i].SalesVersion && sorted_arr[i - 1].MarketingCode == sorted_arr[i].MarketingCode) {
         results.push(sorted_arr[i+1]);
       } else {
         results.push(sorted_arr[i], sorted_arr[i+1]);
       }            
    }
}

console.log(results);

Nina Scholz · Answer 4 · 2018-05-16T07:48:46.827

Basically cou could keep sorting, but with the wanted key, this returns a kind of grouped array, where all wanted keys and their values ar in direct neighbourhood.

Then you could filter the array by checking all keys with the actual value and the predecessor or the successor.

var array = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 }, { name: "Suresh", SalseVersion: 12, MarketingCode: 13 }, { name: "Siva", SalseVersion: 10, MarketingCode: 14 }, { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }],
    keys = ['SalseVersion', 'MarketingCode'],
    result = array
        .sort((a, b) => {
            var d;
            keys.some(k => d = a[k] - b[k]);
            return d;
        })
        .filter((o, i, a) => 
            keys.every(k => a[i - 1] && a[i - 1][k] === o[k]) ||
            keys.every(k => a[i + 1] && o[k] === a[i + 1][k])
        );

console.log(result);

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A single loop approach for unsorted data by using a hash table for temporary collecting the first object of a group or just to indicate duplicates of the group.

var array = [{ name: "Ramesh", SalseVersion: 10, MarketingCode: 11 }, { name: "Suresh", SalseVersion: 12, MarketingCode: 13 }, { name: "Siva", SalseVersion: 10, MarketingCode: 14 }, { name: "Sakthi", SalseVersion: 10, MarketingCode: 11 }],
    keys = ['SalseVersion', 'MarketingCode'],
    result = array.reduce((hash => (r, o) => {
        var key = keys.map(k => o[k]).join('|');
        if (key in hash) {
            if (hash[key]) {
                r.push(hash[key]);
                hash[key] = false;
            }
            r.push(o);
        } else {
             hash[key] = o;
        }
        return r;
    })(Object.create(null)), []);

console.log(result);

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Get duplicated values from an array by checking with two element

4 Answers4