Why the Dot notaion in Objects not working where as Bracket notation works fine?

I am learning about Objects(Dot and Bracket Notations) in JS. I wrote a program that looks up for the ‘value I provided’, in the Object’s list.
Here is the code with Dot Notation:

function lookUp(val) {
  var result = "";
  
  var myDog = {
    "name":  "Anas",
    "tails": "4",
    "bark": "wwof!",
    "breed": "german"
  };
  
  result = myDog.val;
  return result;
}

console.log(lookUp("name"));

The Output of the above program is: Undefined

Here is the same code with Bracket Notation:

function lookUp(val) {
  var result = "";
  
  var lookingUp = {
    "name":  "Anas",
    "tails": "4",
    "bark": "wwof!",
    "breed": "german"
  };
  
  result = lookingUp[val];
  return result;
}

console.log(lookUp('name'));

The Output of the above program is: “Anas” //(The result I wanted)

Why I’m not getting the same output(“Anas”) with Dot Notation?

The dot notation can’t take parameters as properties names.
That’s the reason of the existence of the square brackets notation