Nodejs Utililty Methods Array Different

Array.prototype.diff = function (a, k) {
  return this.filter (function (i) { return a.column (k).indexOf (eval ("i." + k)) < 0; });
};

Array.prototype.diff = function (arr) {
        var mergedArr = this.concat(arr);
        return mergedArr.filter(function (e) {
            return mergedArr.indexOf(e) === mergedArr.lastIndexOf(e);
        });
};

Array.prototype.diff = function(array){
  return this.filter(function(i) {
    if(array){
      return !(array.indexOf(i) > -1)
  })

Array.prototype.diff = function(array) {
    return this.filter(function(e){
        return (array.indexOf(e) < 0 );
    });

Array.prototype.diff = function (init) {
    init = init || 0;
    var g = this;
    return this.reduce(function(prev,cur) {
        prev.push(cur - (prev.length > 0 ? g[prev.length-1] : init));
        return prev;
    },[]);

Array.prototype.diff = function(part) {
    return this.filter(function(element) {return part.indexOf(element) < 0;});
};

Array.prototype.diff1 = function(compare) {
    return this.filter(function(elem) {return elem!=compare;})

function getJSON(yourUrl) {
    var Httpreq = new XMLHttpRequest(); 
    Httpreq.open("GET", yourUrl, false);
    Httpreq.send(null);
    return Httpreq.responseText;
Array.prototype.diffArrays = function(a) {
    return this.filter(function(i) {
        return a.indexOf(i) < 0;
...

function diffArray(arr1, arr2) {
  var newArr = arr1.concat(arr2);
  function checkItems(item) {
    if (arr1.indexOf(item) === -1 || arr2.indexOf(item) === -1) {
      return item;
  return newArr.filter(checkItems);
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);

function diffArray(arr1, arr2) {
  var diff1 = [];
  var diff2 = [];
  diff1 = arr1.filter(function(value) { return arr2.indexOf(value) < 0;});
  diff2 = arr2.filter(function(value) { return arr1.indexOf(value) < 0;});
  return diff1.concat(diff2);
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);