JS console lesson : manipulating numeric arrays

number_array_manipulation.js

// return 2nd highest and lowest numbers
function Second_Greatest_Lowest(arr_num)
{
  arr_num.sort(function(x,y)
           {
           return x-y;
           });
  var uniqa = [arr_num[0]];
  var result = [];
  
  for(var j=1; j<arr_num.length; j++)
  {
    if(arr_num[j-1] !== arr_num[j])
    {
      uniqa.push(arr_num[j]);
    }
  }
  
  result.push(uniqa[1],uniqa[uniqa.length-2]);
  
  return result.join(',');
  
}

console.log(Second_Greatest_Lowest([1,1,2,3,4,4,5,5])); // output: 2, 4