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JavaScript Object-Oriented JavaScript (2015) Constructor Functions and Prototypes Adding a Prototype

Posted by Matt Bloomer
Matt Bloomer
10,608 Points

Can someone help me?

Is anyone working today? Can you please help me?

monster.js 
function Monster(name) {
  this.name = name;
  this.health = 100;
  Monster.prototype{
    this.health--;
  }
}
Matt Bloomer
Matt Bloomer
10,608 Points

When I did add a function, it said that Monster.prototype was not a function; what is the answer to this?

2 Answers

shilohpalomino
PLUS
shilohpalomino
Courses Plus Student 863 Points
shilohpalomino
shilohpalomino
Courses Plus Student 863 Points

Monster.prototype.What? You need to name the property/method you're adding to the prototype. Most likely damage. Is that your question?

Jacob Mishkin
Jacob Mishkin
23,117 Points
Jacob Mishkin
Jacob Mishkin
23,117 Points

Your code needs to look like this:

function Monster(name) {
  this.name = name;
  this.health = 100;
}

Monster.prototype.takeDamage = function(){
  this.health--;
}

what you are doing is taking the takeDamage function out of the Monster constructor function and applying the prototype. The reason for this is so that once the constructor function is called the takeDamage function won't be called multiple times when you create objects based on the constructor function.

the same questions was asked on Treehouse earlier. I think Samuel's post is very useful.

https://teamtreehouse.com/forum/objectoriented-javascript