var array = [1, 2, 1, 10, 5, 3, 4, 40, 50],

     i = array.length,

     result = [];

 array.sort(function (a, b) {

     return a - b;

 });

 for (var i = 0; i < array.length; i++) {

     array[i] != array[i - 1] && array[i + 1] != array[i] && result.push(array[i])

 }

 alert(result);

function fn (arg) {
var result = [];
var obj = {}

for(var i = 0; i < arg.length; i++) {
    obj[arg[i]] = arg[i];
}

for(var i in obj) {
   result.push(obj[i])
}

return result;
}


var arg = fn([22,22,1,2,2,1,1,3,4,5,6,10000, 10000, 1000000,1000000,1000000,1000000,1000000, 'privet', 'privet', 'str', 'str']);

console.log(arg)

Array.prototype.unique = function() {
	return this.filter(function(value, index, _this) {
    	return _this.indexOf(value) === index;
    });
}

alert([1,2,3,3,3,4,5,6,7,7,8,3,4,5,6,1,4,5,8,9,3,2, 'q', 'q', 'aaaa'].unique());

//массив должен быть отсортирован
function f(arg) {
var result = [];

for(var i = 0; i < arg.length; i++) {
   if(arg[i] == result[result.length-1]) continue;
   result.push(arg[i])
}

return result;
}


console.log(f([1,2,2,3,3,5,6]))

alert(Array.from(new Set([1,2,3,1,2,3])))

copy=function(array){return array.map(function(x){return x})}


UnicArray=function(arr){this.array=[]; if(arr) this.add(arr)}
UnicArray.prototype = {
 add: function(array){
   var array=copy(array)
   var tmp
   while(array.length) if(this.array.indexOf(tmp=array.pop()) === -1) this.array.push(tmp)
 },
 show:  function(){ alert(this.array) }
}

myArray=new UnicArray([1,2,3,1,2,3,4])

myArray.show()

myArray=new UnicArray([1,2,3,1,2,3,4])

myArray=new UnicArray([1,2,3,1,2,3,4])