2.js

// Step By Step
function SecondGreatLow (arr) {
    // Use the sort function and pass in a callback to sort from smallest to largest
    // If you haven't encountered function expressions/callbacks before, https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort gives a good explanation of how this method works.
    arr = arr.sort(function (a, b) { return a - b; });
  
    // Loop through each item in the array and check if the adjacent array item is the same.
    for (var i = arr.length - 1; i > 0; i--) {
      if (arr[i] === arr[i - 1]) {
        // If it is, we use the .splice method to remove it.
        arr.splice(i, 1);
      }
    }
  
    if (arr.length > 2) {
      // If our array is longer than two items, we return the 2nd and 2nd to last item in the array.
      return arr[1] + ' ' + arr[arr.length - 2];
    } else if (arr.length === 2) {
      // If our array is exactly two items long, we return the 2nd and the first item
      return arr[1] + ' ' + arr[0];
    } else {
      // If our array is only one item, we return the only element twice.
      return arr[0] + ' ' + arr[0];
    }
  }