Diff Arrays algorithm

diff_2array_v1.js

function diffArray(arr1, arr2) {
  var newArr = [];
  var intersArr = [];
  
  newArr = arr1.filter(function(elem) {
    if(arr2.indexOf(elem) === -1) {
      return true;
    }
    else {
      intersArr.push(elem);
      return false;
    }
  });
 
  arr2.forEach(function(elem) {
    if(intersArr.indexOf(elem) === -1) {
    newArr.push(elem);
  }
  });
  
  return newArr;
}

diff_2array_v2.js

function diffArray(arr1, arr2) {
  var newArr = [];
  var tempArr = [];
  
  newArr = arr1.filter(function(elem) {
    if(arr2.indexOf(elem) === -1) {
      return true;
    }
    else {
      return false;
    }
  });
 
  tempArr = arr2.filter(function(elem) {
    if(arr1.indexOf(elem) === -1) {
      return true;
    }
    else {
      return false;
    }
  });
  
  newArr = newArr.concat(tempArr);  
  
  return newArr;
}