toggle function with ! in jquery

Question

I'm reading someone's source code for their backbone app and trying to figure out this toggle function. I understand the basic of toggle is that it just switches back and forth between a setting. In the example below, it sets the favorite on a model (indicating if it's a favorite or not, I assume). I also understand the use of ! (meaning not). However, I don't get the logic of how this function works.

 toggle: function() {
      this.save({favorite: !this.get("favorite")});
    },

In particular, I don't get the

!this.get("favorite")

Isn't this.get("favorite") returning a string, namely "favorite"? or is this.get("favorite") returning the attribute which is a boolean?

Can someone kindly explain in plain english how the logic of this function works each time it would be called, toggling between the two states.

Answer 1

! is a negation.

The function probably returns a boolean, which result then is inverted.

So in this case it would toggle favorite between true and false