Write a JavaScript program to find the longest string from a given array

function longest_str_in_array(arra)
  {
    var max_str = arra[0].length;
    var ans = arra[0];
    for (var i = 1; i < arra.length; i++) {
        var maxi = arra[i].length;
        if (maxi > max_str) {
            ans = arra[i];
            max_str = maxi;
        }
    }
    return ans;
}
console.log(longest_str_in_array(["ab", "a", "abcd"]));
console.log(longest_str_in_array(["ab", "ab", "ab"]));