using the Function type

var myFunc:Function = function():void{
    trace("test");
}

myFunc.call(); //"test"
myFunc(); //same thing as above

var multiplyWithEight:Function = makeMultiplierOf(8);
var result:Number = multiplyWithEight(2);
trace(result);


public function makeMultiplierOf(x:Number):Function{
    return function(y:Number):Number{
        return x * y; //notice; the function still have access to x when we call it later!
                        //that is a "closure"
    };
}