Calling a function without parentheses returns whole function as a string

Question

I created a JavaScript object like this:

var obj = {
  a: 10,
  b: 20,
  add: function(){
     return this.a + this.b;
  }
};

I executed the

Answer 1

Without parentheses, you're retrieving a reference to the function, you are not calling (executing) the function

With parentheses, you're executing the function.

function a() {
  return 2;
}

var b = a(); // called a, b is now 2;
var c = a; // c is referencing the same function as a
console.log(c); // console will display the text of the function in some browsers
var d = c(); // But it is indeed a function, you can call c(), d is now 2;