Regarding JavaScript function calling

Question

My problem is not with the code here. This code works properly without any errors. But the problem I have is with the function call here.

As far as I know, when calling such a function, first we need to assign it to a variable and then call that variable through console.log(). For example console.log(cc(2)). But without that, the function has been called several times here. How does the output change when the values ​​of the function called without being assigned to that variable are changed? So all the function callings are executed here?

let count = 0;

function cc(card) {
  // Only change code below this line
  switch (card) {
    case 2:
    case 3:
    case 4:
    case 5:
    case 6:
      count++;
      break;
    case 10:
    case "J":
    case "Q":
    case "K":
    case "A":
      count--;
      break;
  }

  var holdbet = "Hold";
  if (count > 0) {
    holdbet = "Bet";
  }
  return count + " " + "holdbet";

  // Only change code above this line
}

cc(2);
cc("K");
cc(10);
cc("K");
cc("A");
console.log(cc(2));

Answer 1

Your function cc modifies the value of a global variable count depending on the value of the argument card passed to it, and returns a string containing the updated value of count concatenated with " holdbet" (As an aside, I think return count + " " + "holdbet"; was meant to be return count + " " + holdbet; to replace holdbet with either "hold" or "bet").

You then make sequential calls to the cc function, passing varying card arguments. Each call will modify the value of count and so a later call with the same argument (2 as the argument in your case) would not necessarily result in the same value of count.

In order to record a return value from cc you must assign it to a variable, which can be done simultaneously with the call:

let result = cc(2); // cc is called, count changes, result stores the value;
cc("K"); // cc is called, count changes, result is unchanged
cc(10);  // cc is called, count changes, result is unchanged
cc("K"); // cc is called, count changes, result is unchanged
cc("A"); // cc is called, count changes, result is unchanged
console.log(cc(2)); // cc is called, count changes, result is unchanged
console.log(result); // value of count at the first call to cc is logged, cc is not called again, count does not change.

in the above example result does not become a function, it becomes a string, the return value of the call to cc.

There may be some confusion caused by the practice of assigning a function to a variable name:

let result = cc; // no call to cc as no (), instead result becomes a function;
console.log(result(2)); // makes a call to cc;