Boolean method with string returns

Question

in this homework i have to do a predicate method that prints a question and then waits for a question. if the user enters no, the method should return false, if the user enters yes the method should return true. I have done that ! but in this part i have problems: if the user enters another thing the program must say something like "wrong answer" and repeat the question. I can't return a string because is a boolean method and i dont know how to resolve this. Thank you!!

import acm.program.ConsoleProgram;
public class YesNo extends ConsoleProgram{
    public void run () {
   String answer = readLine ("would you like instructions? ");
   println (StrBoo (answer));
}


private boolean StrBoo(String answer){
    if (answer.equals("yes")) {
        return true;
    } else if (answer.equals("no")) {
        return false;
    } else { 
    return false;
    }   

}
}

Take in input, check if it is either yes or no, and if it is call your method, if not tell user they entered wrong and prompt them again. Like Luiggi says, you can use a do while for this. — takendarkk
– takendarkk, Commented Aug 18, 2014 at 2:03
Boolean method name should start with "is" , "has", "can", "should".Refer [wiki.eclipse.org/Recommenders/CodingConventions] — Navin a.s
– Navin a.s, Commented Dec 7, 2017 at 6:45

Elliott Frisch · Accepted Answer · 2014-08-18 02:05:39Z

2

First StrBoo is a poor method name. I would call it getAnswer(), and use something like,

private static boolean getAnswer() {
  while (true) {
    String answerStr = readLine ("would you like instructions? ");
    answerStr = (answerStr != null) ? answerStr.trim() : "";
    if ("yes".equalsIgnoreCase(answerStr)) {
      return true;
    } else if ("no".equalsIgnorecase(answerStr)) {
      return false;
    } else {
      System.out.println("Wrong answer");
    }
  }
  return false;
}

answered Aug 18, 2014 at 2:05

Elliott Frisch

202k20 gold badges166 silver badges265 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Luiggi Mendoza Over a year ago

I guess that it's a poor name but now you're breaking encapsulation. Seems like this method should only receive the String as parameter and validate if the string is "yes" or "no" (as shown from the beginning).

Elliott Frisch Over a year ago

@LuiggiMendoza I disagree. The problem as originally phrased also breaks encapsulation, because now the input validation is happening away from the input. I suppose getAnswer() could return null when the input is invalid. As is you'd need 3 values. true, false and not a value. Or you could throw an Exception I guess.

Luiggi Mendoza Over a year ago

Ok I re read it and this seems to be a right implementation. And your statement about returning three values can be met by using Boolean :P (troll part of the comment).

Pawel Os. · Accepted Answer · 2017-11-30 12:49:28Z

The correct design for such kind of program is to throw an exception. Here is an example:

import acm.program.ConsoleProgram;

public class YesNo extends ConsoleProgram 
{
    class WrongAnswerException extends Exception
    {
    }

    public void run ()
    {
        try
        {
            String answer = readLine("would you like instructions? ");
            println(StrBoo(answer));
        }
        catch(WrongAnswerException e)
        {
            println("You have to write yes or no!")
        }
    }

    private boolean StrBoo(String answer) throws WrongAnswerException
    {
        if ("yes".equals(answer))
        {
            return true;
        }
        else if ("no".equals(answer))
        {
            return false;
        }
        else
        {
            throw new WrongAnswerException()
        }
    }
}

Collectives™ on Stack Overflow

Boolean method with string returns

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related