javascript - Get all duplicate values from object array -

i have following object deserialised json data

[{    "employeenumber": "169",    "employeenumbererror": "",    "employeefirstname": "saj"  }, {    "employeenumber": "169",    "employeenumbererror": "",    "employeefirstname": "carlton"  }, {    "employeenumber": "1002",    "employeenumbererror": "",    "employeefirstname": "stanley"  }]

i want duplicate 'employeenumber' object using javascript or jquery. can 1 me?

try this

$(document).ready(function() {    var v = [{      "employeenumber": "169",      "employeenumbererror": "",      "employeefirstname": "saj"    }, {      "employeenumber": "169",      "employeenumbererror": "",      "employeefirstname": "carlton"    }, {      "employeenumber": "1002",      "employeenumbererror": "",      "employeefirstname": "stanley"    }];      var = [];    (x = 0; x < v.length; x++) {      (y = 0; y < v.length; y++) {        if (v[x].employeenumber == v[y].employeenumber) {          a.push(v[x].employeenumber)        }      }      }    = jquery.unique(a);    alert(a[1]);      });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>