Array#uniq 配列の重複した値を間引いた新しい配列を返す

gistfile1.js

// 配列の重複した値を間引いた新しい配列を返す
if (! Array.prototype.uniq) {
    Array.prototype.uniq = function () {
        var that = this.slice(0), len = that.length, storage = {};
        for (len--; len >= 0; len--) {
            if (! storage[that[len]]) {
                storage[that[len]] = true;
            } else {
                that.splice(len, 1);
            }
        }
        return (that.length === 0) ? undefined : that;
    };
}

var org = ('abc def 123 46 0 ghi def GIHUN data dog beta beta 46 69').split(/\s+/);
console.log(org);

var uniq = org.uniq();
console.log(uniq);