How to overload constructor of an Object in JS (Javascript)?

Question

Can I do something like?:

function User(form) {
    this._username = form.username.value;
    this._password = form.password.value;
    this._surname = form.surn         


        

Answer 1

I like Ilya Volodins answer and I thought I would add this as an example:

function foo() {
    var evt = window.event || arguments[1] || arguments.callee.caller.arguments[0];
    var target = evt.target || evt.srcElement;

    var options = {};

    if (arguments[0]) options = arguments[0];

    var default_args = {
        'myNumber'      :   42,
        'myString'      :   'Hello',
        'myBoolean'     :   true
    }
    for (var index in default_args) {
        if (typeof options[index] == "undefined") options[index] = default_args[index];
    }

    //Do your thing

}

//then you call it like this
foo();

//or

foo({'myString' : 'World'});

//or

foo({'myNumber' : 666, 'myString' : 'World', 'myBoolean' : false});

There are probably nicer ways of doing this but this just one example.