Object Oriented questions in Javascript

function User( name, age ){
  this.name = name;
  this.age = age;
}
// Add a new function to the object prototype
User.prototype.getName = function(){
  return this.name;
};
User.prototype.getAge = function(){
  return this.age;
};
var user = new User( "Bob", 44 );
console.log("User: " + user.getName() + ", Age: " + user.getAge());

function User (name, age ) {
  this.name = name;
  this.age = age;
  this.getName = function() {
    return this.name;
  };
  this.getAge = function() {
    return this.age;
  };
}
var user = new User( "Bob", 44 );
console.log("User: " + user.getName() + ", Age: " + user.getAge());

var User = {
  name: "",
  age: 0,
  setName: function(name) {
    this.name = name;
  },
  setAge: function(age) {
    this.age = age;
  },
  getName: function() {
    return this.name;
  },
  getAge: function() {
    return this.age;
  }
};
User.setName("Bob");
User.setAge(44);
console.log("User: " + User.getName() + ", Age: " + User.getAge());

var user = new User("Bob", 44);

function make_user(name, age) {
    return {
        name: name,
        age: age,
        getName: function() { return name; },
        getAge: function() { return age; },
    };
}

var user = make_user("Joe", "18");

function User() {
  return {
    name: "",
    age: 0,
    setName: function(name) {
      this.name = name;
    },
    setAge: function(age) {
      this.age = age;
    },
    getName: function() {
      return this.name;
    },
    getAge: function() {
      return this.age;
    }
  };
}

function User() {
  var age=0;
  var name="";
  return {
    setName: function(name_) {
      name = name_;
    },
    setAge: function(age_) {
      age = age_;
    },
    getName: function() {
      return name;
    },
    getAge: function() {
      return age;
    }
  };
}

User.name = "BoB";
User.age = 44;

person = new User();
person.name = "Bob";
person.age = 44;

var Name = {
  First: "",
  Last: ""
};

Name.prototype.getFullName = function() { return this.First + " " + this.Last; }

var User = {
  name: "",
  age: 0
};

var User = {
  name: "",
  age: 0
};

User.name = 'Bob';
User.age = 44;

console.log("User: " + User.name + ", Age: " + User.age);