confused with the while (! correctGuess)

Sorry first time asking, thought it will show up in the relevant execise section. Heres the code thanks.

var randomNumber = getRandomNumber(10);
var guess;
var guessCount = 0;
var correctGuess = false;

function getRandomNumber( upper ) {
  var num = Math.floor(Math.random() * upper) + 1; 
  document.write(num);
}

do {
  guess = prompt('I am thinking of a number between 1 and 10. What is it?');
  guessCount += 1;
  if (parseInt(guess) === randomNumber) {
    correctGuess = true;
  }  
} while ( ! correctGuess )

document.write('<h1>You guessed the number!</h1>');
document.write('It took you ' + guessCount + ' tries to guess the number ' + randomNumber);

So in your Do While loop you have to "do" the code inside at least once and after that you check the while condition. In your code your while condition is ! correctGuess. If that while condition is true then you continue to "loop" back through the code inside the "do". So, you are correct that while ! correctGuess should evaluate to true.

But it is incorrect to say that do while loop will terminate after 1 guess. If the guess is not === to the randomNumber then correctGuess will still be false since it will skip over that if(parseInt(guess) === randomNumber){...} statement. Only until the guesser guesses the randomNumber will the if(parseInt(guess) === randomNumber) evaluate to true which would make the code inside that if statement to run which would set correctGuess to true.

After the user finally guesses the correct guess then the while conditional ! correctGuess becomes ! true which is false thus ending the Do While loop.