Jquery check if array contains duplicate string

Question

How to check if array contains a duplicate string , i have validateArray = ['sa','sa','yu'] i have used the following function from SO but same not working for me.

checkDuplicate = function (reportRecipients) {
    if (reportRecipients.length > 1) {
        var recipientsArray = reportRecipients.toString().split(',');
        for (a in recipientsArray) {
            if(reportRecipients.indexOf(a) != reportRecipients.lastIndexOf(a)){
                return true;
                break;
            }
        }
    }
    return false;
}

possible duplicate of [Easiest way to find duplicate values in a JavaScript array](http://stackoverflow.com/questions/840781/easiest-way-to-find-duplicate-values-in-a-javascript-array) — adeneo, Apr 10 '14 at 06:04

score 27 · Accepted Answer · answered Apr 10 '14 at 06:20

This is working for me:

var reportRecipients = ['AAA', 'XYZ', 'AAA', 'ABC', 'XXX', 'XYZ', 'PQR'];
var recipientsArray = reportRecipients.sort(); 

var reportRecipientsDuplicate = [];
for (var i = 0; i < recipientsArray.length - 1; i++) {
    if (recipientsArray[i + 1] == recipientsArray[i]) {
        reportRecipientsDuplicate.push(recipientsArray[i]);
    }
}

Hope that helps.

score 2 · Answer 2 · edited Oct 28 '22 at 03:06

2

You can check if an array has duplicates using $.unique function on jQuery.

let len1 = myArray.length; //get the length of your array
let len2 = $.unique(myArray).length; //the length of array removing the duplicates

if (len1 > len2) {
  alert('Found duplicate');
} else {
  alert('Did not find duplicate');
}

edited Oct 28 '22 at 03:06

James Risner

5,451
11
25
47

answered Oct 23 '22 at 17:47

Giorgos Michael

21
1
3

score 0 · Answer 3 · answered Apr 10 '14 at 06:53

Take a look at this:

function getDistinctArray(arr) {
    var compareArray = new Array();
    if (arr.length > 1) {
        for (i = 0;i < arr.length;i++) {
            if (compareArray.indexOf(arr[i]) == -1) {
                compareArray.push(arr[i]);
            }
        }
    }
    return compareArray;
}

And here is a working fiddle

score 0 · Answer 4 · answered Jun 21 '18 at 06:13

Please try this, if the sort function is not working well :

    var all_list= ['sa','sa','yu'] 
    var duplicates_list = [];
    var unique_list = [];
    $.each(all_list, function(key, value){
            if($.inArray(value, unique_list ) == -1){
                unique_list.push(value);
            }else{
                if($.inArray(value, duplicates_list ) == -1){
                    duplicates_list.push(value);
                }
            }
    });

//duplicated elements 
console.log(duplicates_list )

score 0 · Answer 5 · answered Nov 16 '22 at 07:42

    var arr = [1, 2, 3, 4, 4];
    var chk = new Set();
    var duplicates = arr.filter(n => chk.size === chk.add(n).size);
    //console.log(duplicates); // [ 5 ]
    //console.log(duplicates.length); // 1
    if(duplicates.length > 0){
        alert('Duplicate Found');
        return false;
    }
    else{
        return true;
    }

This Working fine. it is the best shortest method .

score -6 · Answer 6 · edited Oct 25 '16 at 09:03

-6

just use unique() method.

$.unique(reportRecipients);

https://api.jquery.com/jQuery.unique/

edited Oct 25 '16 at 09:03

Bhargav Rao

50,140
28
121
140

answered Oct 25 '16 at 09:02

Aster

1

Jquery check if array contains duplicate string

6 Answers6

Linked