利用filter，去除Array的重复元素

var
    r,
    arr = ['apple', 'strawberry', 'banana', 'pear', 'apple', 'orange', 'orange', 'strawberry'];

r = arr.filter(function (element, index, self) {
return self.indexOf(element) === index;
});

console.log(r.toString());
//apple,strawberry,banana,pear,orange