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Java Java Basics Perfecting the Prototype Looping until the value passes

James Young
James Young
775 Points
Posted by James Young
James Young
775 Points

Please help

Hey guys,

I am so confused with this, can someone please help me out and offer some feedback? Thank you all!

KnockKnock.java 
/*  So the age old knock knock joke goes like this:

    Person A:  Knock Knock.
    Person B:  Who's there?
    Person A:  Banana
    Person B:  Banana who?
    ...as long as Person A has answered Banana the above repeats endlessly
    ...assuming the person answers Orange we'd see
    Person B:  Orange who?
    ...and then the punchline.
    Person A:  Orange you glad I didn't say Banana again?
    (It's a really bad joke that makes it sound like "Aren't you glad I didn't say Banana again?")

    Let's just assume the only two words passed in from the console from Person B are either banana or orange.
*/

// ====BEGIN PROMPTING CODE====

// Person A asks:
console.printf("Knock Knock.\n");

// Person B asks and Person A's response is stored in the String who:
String who = console.readLine("Who's there?  ");

// Person B responds:
String answer = console.readLine("banana");
console.printf("%s who?\n", who);



// ==== END PROMPTING CODE ====

3 Answers

Richard Ling
Richard Ling
8,522 Points
Richard Ling
Richard Ling
8,522 Points

Hi James,

This one actually really confused me too, so you're not alone! I guess I just wasn't very familiar with the joke haha. I ended up with:

// ====BEGIN PROMPTING CODE====



String who = "";
do {
  // Person A asks:
  console.printf("Knock Knock.\n");
  // Person B asks and Person A's response is stored in the String who:
  who = console.readLine("Who's there?  ");
  // Person B responds:
  console.printf("%s who?\n", who);
} while(who.toLowerCase() == "banana");


// ==== END PROMPTING CODE ====

Basically, the line asking "Who's there?" is to be repeated as long as the answer given is "banana". The Do-While repeats that line until the While condition is no longer true.

So to start, the variable who is empty, the loop starts and the user is prompted for input. They enter banana, the while condition checks to see if the lower case version of their input is "banana". If it is, is repeats the code; if not, the loop ends.

:)

I left one line outside the loop, so have edited to move it back in :P

Craig Dennis
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

Psst...use who.equalsIgnoreCase("banana")

Richard Ling
Richard Ling
8,522 Points
Richard Ling
Richard Ling
8,522 Points

Haha, oops, yes quite right Craig, thanks for the heads up ;)

James Young
James Young
775 Points
James Young
James Young
775 Points

Hey Rich,

Thank you so much for all of your help, I really appreciate it. Its a little confusing but I think after some practice I will get the hang of it...Thank you again!

Best wishes, James

James Young
James Young
775 Points
James Young
James Young
775 Points

Thank you for the tip Craig, I really appreciate it!... Keep up the great work, you are awesome!!

Best wishes james