how to get all the unique values from a string array in javascript code example

Example 1: how to find unique elements in array in javascript

let a = ["1", "1", "2", "3", "3", "1"];
let unique = a.filter((item, i, ar) => ar.indexOf(item) === i);
console.log(unique);

Example 2: 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;
}