<script src="//code.jquery.com/jquery.min.js"></script>

<script>

var arr1 = ['A', 'B', 'C', 'D'];

var arr2 = ['C', 'D', 'E', 'F'];

​

$.union = function(a,b){return $(a).add(b).get();};

$.intersect = function(a,b){return $.grep(a,function(i){return $.inArray(i,b)>-1;});};

$.complement = function(a,b){return $(a).not(b).get()};

$.sym_diff = function(a,b){return $(arr1).add(arr2).not($.intersect(arr1,arr2)).get();};

​

$(function() {

  // Union

  console.log( $.union(arr1, arr2) );

  // ["A", "B", "C", "D", "E", "F"]

​

  // Intersection

  console.log( $.intersect(arr1, arr2) );

  // ["C", "D"]

​

  // Complement

  console.log( $.complement(arr1, arr2) );

  // ["A", "B"]

​

  // Symmetric difference

  console.log( $.sym_diff(arr1,arr2) );

  // ["A", "B", "E", "F"]

});

</script>