Remove duplicates in array separated by double commas in JavaScript

Question

I have an array in JavaScript like this

var data = [,A_1_VII,VII,V2,,A_1_VII,VII,V2,,A_1_VII,VII,V2,,B_1_XIV,XIV,V3,,B_2_XVI,XVI,V3]

when I alert in JavaScript it gives as below

,A_1_VII,VII,V2
,A_1_VII,VII,V2
,A_1_VII,VII,V2
,B_1_XIV,XIV,V3
,B_2_XVI,XVI,V3

But I want like this which is duplicates removed array

var unique_data = [,A_1_VII,VII,V2,,B_1_XIV,XIV,V3,,B_2_XVI,XVI,V3]

On alert it should give like this

,A_1_VII,VII,V2
,B_1_XIV,XIV,V3
,B_2_XVI,XVI,V3

What have you tried so far? Also your current JS example will throw an error. — evolutionxbox, Nov 14 '17 at 10:27
That is a really strange javascript array. Is this code valid javascript? — Jasper Seinhorst, Nov 14 '17 at 10:27
@DontVoteMeDown I doubt that variable names can start with a comma. — Bojan Ivanac, Nov 14 '17 at 10:29
@BojanIvanac it works for me: https://i.stack.imgur.com/TAWPT.png — DontVoteMeDown, Nov 14 '17 at 10:31
Actually I am storing in that format in array so I can able to send this data to front end side easily. And this is how I am pushing into array, data.push(["",my_data.id,my_data.class,my_data.name]); — bioinform, Nov 14 '17 at 10:31
Already answered https://stackoverflow.com/questions/9229645/remove-duplicates-from-javascript-array?page=1&tab=oldest#tab-top — Bheru Lal Lohar, Nov 14 '17 at 10:31
You can't check for duplicates by variables names, only by values. — DontVoteMeDown, Nov 14 '17 at 10:32
@BojanIvanac: No, but arrays can have empty entries in them, which is what that array has. (This is as of ES2015+) For example: `[,,,1,,,]` is perfectly valid (in ES2015+). — T.J. Crowder, Nov 14 '17 at 10:32
@bioinform Are the values you want to stay unique always in groups of 3? — Bojan Ivanac, Nov 14 '17 at 10:35
why not using an array of objects ? It would be way easier like `data.push(my_data)` resulting in `[{ id: 'value', class: 'value', name: 'value' }]` — 3Dos, Nov 14 '17 at 10:37
@BojanIvanac in groups of 3 considered as 1 item in my array. — bioinform, Nov 14 '17 at 10:37
@bioinform and the groups are always separated by a double comma right? — Bojan Ivanac, Nov 14 '17 at 10:38
check that alert thing which I included. For every three items internally separated by a comma but when it comes one item to another, one more comma is there which separates group of three into one item. — bioinform, Nov 14 '17 at 10:41

score 1 · Answer 1 · answered Nov 14 '17 at 10:39

Assuming the variables in your array are well defined, you can clean it up and remove duplicates with a for loop:

var data [/* ... */];
var unique_data = [];

for(let i = 0; i < data.length; i++) {
    if (data[i] && unique_data.indexOf(data[i]) === -1) {
        unique_data.push(data[i]);
    } 
}

Please note that the code above assumes that your array contains non-object types, otherwise the solution would need to use something more sophisticated than indexOf().

score 1 · Accepted Answer · answered Nov 14 '17 at 10:41

1

First Thing your array contains string as a constant that's not going to work.

Secondly, if all of you value are strings you can do it as follows:

var data =[,"A_1_VII","VII","V2",,"A_1_VII","VII","V2",,"A_1_VII","VII","V2",,"B_1_XIV","XIV","V3",,"B_2_XVI","XVI","V3"];

var uniqueArray = data.filter(function(item, pos) {
    return data.indexOf(item) == pos;
})

alert(uniqueArray);

answered Nov 14 '17 at 10:41

Bheru Lal Lohar

880
9
17

Not working man. I tried this already. Now also again I tried. But not working. – bioinform Nov 14 '17 at 10:46
@bioinform did you put all your values into double quotes, as above codes are working fine click on "Run code snippet" – Bheru Lal Lohar Nov 14 '17 at 10:49

4b0 · Answer 3 · 2017-11-14T10:54:05.640

You can create your unique function to remove duplicate entry and empty value from array like this.

var data =[,"A_1_VII,VII","V2,,A_1_VII","VII","V2",,"A_1_VII","VII","V2",,"B_1_XIV,XIV","V3",,"B_2_XVI,XVI,V3"]   
var unique_data = uniqueList(data);
alert(unique_data);
function uniqueList(list) {
  var uniqueResult = [];
  $.each(list, function(i, e) {
    if ($.inArray(e, uniqueResult) == -1 &&$.inArray(e, uniqueResult)!="")// chech for unique value and empty value
      uniqueResult.push(e);
  });
  return uniqueResult ;
}

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Remove duplicates in array separated by double commas in JavaScript

3 Answers3