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Java Java Basics Perfecting the Prototype Looping until the value passes

Posted by David Santos
David Santos
1,486 Points

can you insert 2 boolean simultaneously? e.g boolean isBanana; boolean isOrange;

// i wonder if you have to boolean simultaneously e.g. String noun; boolean isBanana; boolean isOrange; do { console.printf("Knock Knock. \n"); who = console.readLine("Who's there? \n"); isBanana = (who.equalsIgnoreCase('banana'")); isOrange = (who.equalsIgnoreCase("orange")); }while(isBanana); if (isOrange) {

console.printf("%s who? \n"); console.printf("%s you glad i didn't say banana anymore? \n"); }

//is something like that do able?

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====
String noun;
boolean isBanana;
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?  ");
  isBanana = (who.equalsIgnoreCase("banana"));
}while(isBanana);
// Person B responds:
console.printf("%s who?\n", who);
console.printf("Orange you glad i didn't say Banana anymore? \n");
// ==== END PROMPTING CODE ====
David Santos
David Santos
1,486 Points 
      String who; 
      boolean isBanana; 
      boolean isOrange; 
      do { 
        console.printf("Knock Knock. \n"); 
        who = console.readLine("Who's there? \n"); 
        isBanana = (who.equalsIgnoreCase("banana")); 
        isOrange = (who.equalsIgnoreCase("orange"));
      }while(isBanana); 
        if (isOrange);{

          console.printf("%s who? \n", who); 
          console.printf("%s you glad i didn't say banana anymore? \n", who); 
        }
    }
}
//yup, tried it and it works this way too.

1 Answer

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

Hi David,

Well let's think that through a bit. Is there ever a case where those would both be true? I think what you might be getting at is checking to make sure that they entered orange. One thing you can do is negate a boolean. This is done by putting an exclamation mark in front of it. So what this code does is loop until the user enters orange.

// ...
boolean isOrange;
do {
// ...
     isOrange = who.equalsIgnoreCase("orange");
} while(! isOrange);

Since we didn't cover negation in Java Basics, this is not expected to be needed. Also to try and keep things simple the instructions state:

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

Great job thinking outside the box!

David Santos
David Santos
1,486 Points

Hey, thanks Craig. That negation thing is superb.