var array1 = ['a', 'c','d','f','h']; var array2 = ['a','b', 'c','d','e','f','g','h']; document.write('array 1 : '+array1+'<br>'); document.write('array 2 : '+array2+'<br>'); //prototype method for array to find and remove matched element from argument array. Array.prototype.diff = function(arr2) { this.sort(); arr2.sort(); for(var i = 0; i < this.length; i += 1) { if(arr2.indexOf( this[i] ) > -1){ arr2.splice(arr2.indexOf( this[i] ), 1); } } }; //code usage for above prototype method. array1.diff(array2); document.write('result array : '+array2); //Note : I have used document.write() method to just show the out put in screen. But using document.write() is not recommended.