closure.object.js

var person = (function() {
    var name, lastname;
    
    function get(key) {
        switch(key) {
            case 'name': return name; break;
            case 'lastname': return lastname; break;
            default: return null
        }    
    }
    
    function set(key, value) {
        switch(key) {
            case 'name': name = value; return name; break;
            case 'lastname':  lastname = value; return lastname; break;
            default: return null
        }    
    }
    
    return function(method, args) {
        args = args || [];
        
        if(method == 'get') {
            return get(args[0]);
        }
       
        if(method == 'set') {
            return set(args[0], args[1]);
        }
    }
})()

console.log('GET name ', person('get', ['name']));
console.log('SET name ', person('set', ['name', 'Joe']));
console.log('GET name ', person('get', ['name']));