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Java Java Basics Perfecting the Prototype Looping until the value passes

Posted by Scott Schopman
Scott Schopman
4,027 Points

Stuck on Stage 3 challenge: can't figure out the do while loop...

Just can't figure out how to properly write this out... Feel like a dummy!

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Scott,

Can you post what code you've attempted?

Scott Schopman
Scott Schopman
4,027 Points

Hey Jason,

Thanks for answering...

What I was working off of is this...

String who;
do {
  console.printf("Knock Knock.\n");
  who = console.readLine("Who's there?  ");
  console.printf("%s who?\n", who);
} while (who.equalsIgnoreCase("banana");
Scott Schopman
Scott Schopman
4,027 Points

I think i just need a better explanation of the reason and placement of "do" "if" and "while"... I just get lost why things go where they go and why they are used.

Ken Alger
Ken Alger
Treehouse Teacher
Ken Alger
Ken Alger
Treehouse Teacher

Scott;

I see that you requested an answer from me and that others have provided some great information. Let us know if the "do" and "if/while" concepts are still muddy. They are, in my opinion, essential building blocks for much of Java and programming in general.

Ken

Scott Schopman
Scott Schopman
4,027 Points

Hey Ken,

My problem is just I can't conceptualize it when a problem is presented to me. I understand it all going through all the videos, quizzes and some excersises but as soon as I am presented something like this, I just go blank and have no idea what to type. I know there needs to be a "do" and "while" etc. and I can remember the placement of them from the videos but for some reason I just can't get my brain wrapped around where to properly place and structure everything to get it to work properly... Guess it just takes more time.

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Do you understand the code that you posted above? Let us know if you don't.

That code is correct except you're missing the closing parenthesis on the while condition.

As long as you read the code challenge instructions carefully I think they do a pretty good job of guiding you to the solution.

I think you'll get better at the placement of things as you gain more practice.

1 Answer

David Postlethwaite
David Postlethwaite
9,355 Points

Scott, in this loop we look at the do statement as do this, while the answer is this(banana) execute this code. So in the challenge the do is print Knock Knock, while the person answers banana we display banana who. In the next stage they will incorporate the if statement that will change the reply if the person answers "Orange". the code should for this challenge be:

String who;
do {
  console.printf("Knock Knock.\n");
  who = console.readLine("Who's there?  ");

    }while(who.equalsIgnoreCase("Banana"));
      console.printf("%s who?\n", who);

Hope this helps, if seems as clear as mud then sorry I can try to explain again.

Scott Schopman
Scott Schopman
4,027 Points

Thanks so much David!