Confused about the correctGuess = true;

Hello Richard.

Looking at the first statement, the correctGuess variable was initialized with value false. On the next line, the random number was also initialized and a random valua was also assigned to it.

Now, I believe the tricky part comes in on the fourth line with the first if statement. Understand that this if statement will only be executed when the value entered by the user is equal to the randomly generated number. Executing that block of code will change the default/initial value of the correctGuess variable to true.

The second if statement on the seventh line will either execute the if block or the else block depending on the state/value of the correctGuess variable.

var correctGuess = false;
var randomNumber = Math.floor(Math.random() * 6 ) + 1;
var guess = prompt('I am thinking of a number between 1 and 6. What is it?');
if (parseInt(guess) === randomNumber ) {
  correctGuess = true;
} 
if ( correctGuess ) {
    document.write('<p>You guessed the number!</p>');
} else {
    document.write('<p>Sorry. The number was ' + randomNumber + '.</p>');
}

I hope this helps. Feel free to comment again if you still don't understand it.