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Java Java Basics Perfecting the Prototype Looping until the value passes

Posted by Shivang Chaturvedi
Shivang Chaturvedi
2,600 Points

I need some help in this exercise. I cannot compile it. Can anyone assist me on this?

I cannot implement the do while loop correctly. So need some help to make the progress. Would be great if someone can tell me what corrections can be made if I add the following command line-

String who; boolean invalidKeyword;

do { invalidKeyword = (who.equalsIgnoreCase("Banana")); if(invalidKeyword) {

console.printf("Banana Who?\n"); } } while(ignoreKeyword);

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:


// Person B responds:
String who;
  boolean invalidKeyword;
  do
  {
    who = console.readLine("Who's there?  ");
    If(who.equalsIgnoreCase("Banana"));
    {
      console.printf("Banana who? \n");
    }
  }
  while (invalidKeyword);
  console.printf("%s you glad I didn't say Banana again?", who);
}
// ==== END PROMPTING CODE ====

2 Answers

William Li
PLUS
William Li
Courses Plus Student 26,868 Points
William Li
William Li
Courses Plus Student 26,868 Points

Hi, Shivang Chaturvedi , your code has several syntax errors.

  • keyword if is misspelled
  • misplacing ;
  • 2 { and 3 } 
// ====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:
console.printf("%s who?\n", who);

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

So the challenge provides you with this code template. You only need to do a few things here.

  1. wrap all the codes in the do...while loop
  2. move String who declaration outside of the loop to avoid scope issue.
  3. add a while condition check.
String who;
do {
    console.printf("Knock Knock.\n");
    who = console.readLine("Who's there?  ");
    console.printf("%s who?\n", who);
} while (who.equalsIgnoreCase ("banana"));

That's pretty much it for this part of the challenge.

Shivang Chaturvedi
Shivang Chaturvedi
2,600 Points

@William Li - Thanks a lot for the help. Really appreciate it.

James Simshaw
James Simshaw
28,738 Points
James Simshaw
James Simshaw
28,738 Points

The first thing I see is that invalidKeyword is never set yet you're calling its value.