Function overloading in Javascript - Best practices

Question

What is the best way(s) to fake function overloading in Javascript?

I know it is not possible to overload functions in Javascript as in other languages. If I neede

Answer 1

I just tried this, maybe it suits your needs. Depending on the number of the arguments, you can access a different function. You initialize it the first time you call it. And the function map is hidden in the closure.

TEST = {};

TEST.multiFn = function(){
    // function map for our overloads
    var fnMap = {};

    fnMap[0] = function(){
        console.log("nothing here");
        return this;    //    support chaining
    }

    fnMap[1] = function(arg1){
        //    CODE here...
        console.log("1 arg: "+arg1);
        return this;
    };

    fnMap[2] = function(arg1, arg2){
        //    CODE here...
        console.log("2 args: "+arg1+", "+arg2);
        return this;
    };

    fnMap[3] = function(arg1,arg2,arg3){
        //    CODE here...
        console.log("3 args: "+arg1+", "+arg2+", "+arg3);
        return this;
    };

    console.log("multiFn is now initialized");

    //    redefine the function using the fnMap in the closure
    this.multiFn = function(){
        fnMap[arguments.length].apply(this, arguments);
        return this;
    };

    //    call the function since this code will only run once
    this.multiFn.apply(this, arguments);

    return this;    
};

Test it.

TEST.multiFn("0")
    .multiFn()
    .multiFn("0","1","2");