using _.unique Return a new array of all elements from <array> with duplicates removed also using _.indexOf JavaScript code example
Example: how to get unique values from array in javascript without duplicate value
function uniqueArray2(arr) {
var a = [];
for (var i=0, l=arr.length; i<l; i++)
if (a.indexOf(arr[i]) === -1 && arr[i] !== '')
a.push(arr[i]);
return a;
}