Duplicates in object array

Question

EDITED!!

I have an object array:

Array 0:[{id:"a1" , code:"123" , name:"a"},
         {id: "a2", code: "222" , name: "a"},
          {id: "b1", code: "433", name: "b"}]
Array 1:[{id:"a1" , code:"123" , name:"a"},
         {id: "b2", code: "211" , name: "b"},
          {id: "b1", code: "433", name: "b"}]

I want to get the array of object that has no duplicate value for "name". and store it to another array:

Result:
Array 0:{id: "b1", code: "433", name:"b"}
Array 1: {id:"a1" , code:"123" , name:"a"}

How can I get the array of object that has no duplicate value for name ? All I found on some thread is to remove duplicates from array and not get the array with no duplicate. Thanks in advance!

alexpods · Answer 1 · 2015-01-23T15:24:51.293

1

function filterByName(array) {
    var counts = {};

    array.forEach(function(obj) { 
        counts[obj.name] ? ++counts[obj.name] : (counts[obj.name] = 1);
    });

    return array.filter(function(obj) { 
        return counts[obj.name] === 1;
    });
}

var filteredArray1 = filterByName(array1);
var filteredArray2 = filterByName(array2);

Explanation of function

Create temporary counts object for keeping counts of object with the same name.
Fill this object with data by using standard forEach method of array.
Filter array by using standard filter method

UPD You need this if I understand your question correctly at last:

var filteredArray = arrayOfArrays.map(function(arrayOfObjects) {
  return filterByName(arrayOfObjects)[0];
});

edited Jan 23 '15 at 15:24

answered Jan 22 '15 at 03:12

alexpods

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can you explain this sir? – Lew Jason Nuyda Jan 22 '15 at 03:27
there's an error that says 'Invalid left-hand side in assignment' for the line `return !temp[obj.name] && temp[obj.name] = true;` – Lew Jason Nuyda Jan 22 '15 at 03:35
@LewJasonNuyda: Operator precedence. Use `return !temp[obj.name] && (temp[obj.name] = true);` instead. – Felix Kling Jan 22 '15 at 03:41
@FelixKling Yeah, I forget about precedence – alexpods Jan 22 '15 at 03:43
@FelixKling Done, explanation is added. – alexpods Jan 22 '15 at 03:51
appreciated all your answer... when I tried `console.log(temp)` all I got are ` Object {a: true, b: true}` what I need is only the array value that has no duplicate for object `name` – Lew Jason Nuyda Jan 22 '15 at 03:57
@alexpods for `array` should I use my `array` ? what should I check for the result? – Lew Jason Nuyda Jan 22 '15 at 05:33
i forgot to tell you. that those array object from my example was only a single array that needs to be compare. meaning there is next array set that have the same array objects. – Lew Jason Nuyda Jan 22 '15 at 05:39
@LewJasonNuyda Update the answer. Using `filterByName` function you can filter as many arrays as you want. – alexpods Jan 22 '15 at 08:44
@alexpods No, you don't get what I need. Let me explain, I have an array for each array, I have 3 array objects and I should get the array objects that has distinct name value. – Lew Jason Nuyda Jan 23 '15 at 02:43

Duplicates in object array

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