memorize

function memorize(f){
                var cache = {};
                return function(){
                    var key = arguments.length + Array.prototype.join.apply(this,arguments);
                    if(key in cache){

                        return cache[key];
                    } else{
                        return cache[key] = f.apply(this, arguments);
                    }
                }
            }
            function add(a,b){
                return a + b;
            }
            var adder = memorize(add);
            for(var i=0;i<4;i++){
                console.log(adder(1,2));
            }