Why is the function called without parentheses?

Question

JavaScript

function makeCounter() {
  var currentCount = 1;

  function counter() {
      return currentCount++;
    }

  counter.set = function(value) {
    currentCount = value;
  };

  counter.reset = function() {
    currentCount = 1;
  };

  return counter; // Интересует этот момент
}

var counter = makeCounter();

alert( counter() ); // 1
alert( counter() ); // 2

counter.set(5);
alert( counter() ); // 5

I used to think that if a function is called without parentheses, then this is in order to show the code of the function, but in this case this is not so.

Answer 1

"return counter;" it's not a function call, it's returned by the object/function "function counter".
But further "counter()" is the call to this function "function counter()"

Answer 2

I will say this. Counter without brackets is a REFERENCE to a function \ object and counter(), that is, respectively, with brackets, this is the call itself. You return a reference to the counter function from the function and not its call, this is so that it can be called further in the code. And since it has a function = object and the methods that you assigned, here is also the rule, you only need a counter without parentheses so that you can call the METHODS of the object.
And after the scope of the function there are already parentheses. We want to increase the currentCounter =+ 1 variable, then we call the count () function. We want a reset or a method of this function, then we call counter.reset (). Otherwise, the result of counter().reset() would be

Answer 3

So alert( counter() ); and displays the result of the function execution.