CODEWITHSUNDEEP
javascriptlodash
mymotherland
mymotherland

Reputation: 8228

Remove duplicate value from nested object using javascript

I have a million of contacts which is from different group. For example

    {"GROUP":[{'G1: [C1,C2,C3........C500000]},
             {'G2': [C1,C2,C3........C500000,D1,D2,D3........D500000]}
.....]
    }

G1 has 500k contacts, G2 has 1 million contacts out of it 500k contacts which is already present in G1.

I want to filter above group object based on the condition, "Contact which is already in any group should be checked and remove from respective group".

Expected Result

 {"GROUP":[{'G1: [C1,C2,C3........C500000]},
             {'G2': [D1,D2,D3........D500000]},....]
    }

Here Group and its contact may increase in size.

What is the best way to implement it using lodash javascript?

Upvotes: 0

Views: 856

Answers (2)

Ori Drori
Ori Drori

Reputation: 191976

If you don't know how many items from previous object, will be included in the next, you can use _.difference() with an external array, which will store all existing items:

var object = {
    group: [
        { g1: ['c1', 'c2', 'c3', 'c4', 'c5']},
        { g2: ['c1', 'c4', 'c5', 'd1', 'd2', 'd3', 'd4', 'd5']},
        { g3: ['c1', 'c3', 'c4', 'c5', 'd1', 'd4', 'd5', 'e1', 'e2', 'e3', 'e4', 'e5']}
    ]
};

var previousItems = [];

var group = object.group.map(function(item) {
  return _.mapValues(item, function(values) {
    var newValues = _.difference(values, previousItems);
    previousItems = previousItems.concat(newValues);
    return newValues;
  });
});

console.log(group);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

If all items in the previous object are included in the next, you can use a simple Array#slice:

var object = {
    group: [
        { g1: ['c1', 'c2', 'c3', 'c4', 'c5']},
        { g2: ['c1', 'c2', 'c3', 'c4', 'c5', 'd1', 'd2', 'd3', 'd4', 'd5']},
        { g3: ['c1', 'c2', 'c3', 'c4', 'c5', 'd1', 'd2', 'd3', 'd4', 'd5', 'e1', 'e2', 'e3', 'e4', 'e5']}
    ]
};

var prevValues = [];

var group = object.group.map(function(item, index) {
  return _.mapValues(item, function(values) {
    var newValues = values.slice(prevValues.length);
    prevValues = values;
    return newValues;
  });
});

console.log(group);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Upvotes: 1

Sven Liebig
Sven Liebig

Reputation: 838

After a long process of thinking, i have this for you:

It automatically goes throught the object / array structure and removes the duplicated strings in the array of g1, g2, g3, ... and so on.

I never used lodash, so here is vanilla js.

var object = {
    group: [
        { g1: ['a', 'b', 'c', 'd']},
        { g2: ['a', 'b', 'c', 'd', 'e', 'f', 'g']},
        { g3: ['f', 'g', 'h', 'i', 'j', 'k', 'l']}
    ]
};

var duplicateArray = [];

for(var key in object) {
  var group = object[key];
  
  for(var x = 0; x < group.length; x++) {
      var subGroup = group[x];
      
      for(var subkey in subGroup) {
          var contentArray = subGroup[subkey];
          
          for(var y = 0; y < contentArray.length; y++) {
              var value = contentArray[y];
          
              if(duplicateArray.indexOf(value) == -1) {
                  duplicateArray.push(value);
              } else {
                  object[key][x][subkey].splice(y, 1);
                  y -= 1;
              }
          }
      }
  }
}

console.log(`dub ${duplicateArray}`);
console.log(object);

Upvotes: 1

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