How can I get form data with JavaScript/jQuery?

Question

Is there a simple, one-line way to get the data of a form as it would be if it was to be submitted in the classic HTML-only way?

For example:

Answer 1

For those of you who would prefer an Object as opposed to a serialized string (like the one returned by $(form).serialize(), and a slight improvement on $(form).serializeArray()), feel free to use the code below:

var Form = {
    _form: null,
    _validate: function(){
        if(!this._form || this._form.tagName.toLowerCase() !== "form") return false;
        if(!this._form.elements.length) return false;
    }, _loopFields: function(callback){
        var elements = this._form.elements;
        for(var i = 0; i < elements.length; i++){
            var element = form.elements[i];
            if(name !== ""){
                callback(this._valueOfField(element));
            }
        }
    }, _valueOfField: function(element){
        var type = element.type;
        var name = element.name.trim();
        var nodeName = element.nodeName.toLowerCase();
        switch(nodeName){
            case "input":
                if(type === "radio" || type === "checkbox"){
                    if(element.checked){
                        return element.value;
                    }
                }
                return element.value;
                break;
            case "select":
                if(type === "select-multiple"){
                    for(var i = 0; i < element.options.length; i++){
                        if(options[i].selected){
                            return element.value;
                        }
                    }
                }
                return element.value;
                break;
            case "button":
                switch(type){
                    case "reset": 
                    case "submit": 
                    case "button":
                        return element.value;
                        break;
                }
                break;
        } 
    }, serialize: function(form){
        var data = {};
        this._form = form;

        if(this._validate()){
            this._loopFields(function(value){
                if(value !== null) data[name] = value;
            });
        }
        return data;
    }
};

To execute it, just use Form.serialize(form) and the function will return an Object similar to this:

As a bonus, it means you don't have to install the entire bundle of jQuery just for one serialize function.