'do...while loops'

Question

Can anyone please explain the effect of the boolean value here in a different or more thorough way? Can't wrap my head around how the while (! correctGuess) causes the document to write that you were correct, or.....anything about the partial while loop at the end .........what's going on?

Nikica Maksimovski · Accepted Answer

That's the way do while loops work, the block of code in the do will be executed until the condition in the while is true.
Once we make the right guess, we don't want to make any guesses so we manually change the flag from false to true, so when we check the condition again it returns false so the loop stops.
Not the while(!correctGuess) causes the document to write that you were correct, but it just stops the loop from asking you for guesses once you made the correct guess.If you don't understand the "!" sign you could just write "while(correctGuess === false)" and it will work the same way.
I believe you understand the concept now.

Missy Kailet · Answer

The following are the same:
JavaScript
while(correctGuess)

JavaScript
while(correctGuess === true)

JavaScript
while(!correctGuess === false)

And the following are the opposite of the above:
JavaScript
while(!correctGuess)

JavaScript
while(!correctGuess === true)

JavaScript
while(correctGuess === false)

Which means, "while correctGuess IS NOT true."
Which, in this example, while the player does not guess the right number, causing the variable correctGuess to remain false, execute the "ask the player to guess" code.
JavaScript
guess = prompt('guess the number'); //receives user input and stores in "guess"
//...
if( guess === randomNumber) //player guessed the randomly generated number
{ correctGuess = true } //change correctGuess to true, so that "while NOT TRUE correctGuess" is no longer a valid statement

JavaScript
while(!correctGuess) //while NOT TRUE correctGuess, another way of saying while FALSE correctGuess

If you'd like a better explanation of why "while(correctGuess)" with no ! in front of it would evaluate to true, or is the same as "while(correctGuess === true)", feel free to read the following article.
https://www.sitepoint.com/javascript-truthy-falsy/
I hope that helped...

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Teacher Russell

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'do...while loops'

2 Answers

Nikica Maksimovski

Nikica Maksimovski

Teacher Russell

Teacher Russell

Missy Kailet

Missy Kailet

Teacher Russell

Teacher Russell