Move an element frome an array up or down.

move.js

var move = function(array, element, delta) {
  var index = array.indexOf(element);
  var newIndex = index + delta;
  if (newIndex < 0  || newIndex == array.length) return; //Already at the top or bottom.
  var indexes = [index, newIndex].sort(); //Sort the indixes
  array.splice(indexes[0], 2, array[indexes[1]], array[indexes[0]]); //Replace from lowest index, two elements, reverting the order
};

var moveUp = function(array, element) {
  move(array, element, -1);
};

var moveDown = function(array, element) {
  move(array, element, 1);
};

//Test
var array = [1, 2, 3, 4, 5];
moveUp(array, 4);
moveUp(array, 2);
moveDown(array, 5);

Thanks, you helped me a lot!

Thanks soo much, very helpful.

A better alternative to move by index directly
(also fixed the issue when moving with index 10)

move(array, index, delta) {
      //ref: https://gist.github.com/albertein/4496103
      console.log('move', array, index, delta);

      var newIndex = index + delta;
      if (newIndex < 0 || newIndex == array.length) return; //Already at the top or bottom.
      var indexes = [index, newIndex].sort((a, b) => a - b); //Sort the indixes (fixed)
      array.splice(indexes[0], 2, array[indexes[1]], array[indexes[0]]); //Replace from lowest index, two elements, reverting the order
    },