Avoid Adding Methods And Properties To Custom Object

I'm using a base custom object extended with prototype function Person() {} Person.prototype.Name = ''; Person.prototype.Lastname = ''; var NewPerson= new Person(); NewPer

Solution 1:

I found freeze and seal but those prevent me from changing the values.

Values can be changed with Object.seal

The Object.seal() method seals an object, preventing new properties from being added to it and marking all existing properties as non-configurable. Values of present properties can still be changed as long as they are writable.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/seal

http://plnkr.co/edit/Wut7lsOxdFuz2VzsFzCM?p=preview

function Person(){
  this.name = "";
  this.id = "";
  Object.seal(this);
}

var p1 = new Person();

p1.name = "Mike";
p1.id = "A1";
p1.age = 32;

console.log(p1); //Person {name: "Mike", id: "A1"}

If you desire to actually freeze the prototype of the object while leaving other parts writable then you can try this approach

function Person(){
  this.name = "";
  this.id = "";
  Object.seal(this);
}

//this will add to Person
Person.prototype.test = function(){
  alert("hi");
}

Object.freeze(Person.prototype);

//this won't
Person.prototype.test2 = function(){
  alert("hi");
}

var p1 = new Person();


p1.name = "Mike";
p1.id = "A1";
p1.age = 32;

console.log(p1); //Person {name: "Mike", id: "A1"} test will be on the proto