Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Java Java Objects (Retired) Delivering the MVP Validation

ms2030
ms2030
2,973 Points

What's wrong with this code challenge?

Error reported: Bummer! "mFirstName" should have passed but invalid field name was reported.

I tested it with java-repl and it works.

TeacherAssistant.java
public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {
    // These things should be verified:
    // 1.  Member fields must start with an 'm'
    // 2.  The second letter in the field name must be uppercased to ensure camel-casing
    // NOTE:  To check if something is not equal use the != symbol. eg: 3 != 4
    if (!(fieldName.indexOf(0) == 'm' && Character.isUpperCase(fieldName.toCharArray()[1]))) {
      throw new IllegalArgumentException("Invalid field name");     
    }

    return fieldName;
  }

}

2 Answers

Harry James
Harry James
14,780 Points

Hey ms2030!

If you change the && in your if statement to a || then the challenge will pass :)

The reason being is that the code challenge will want to throw an exception if either the first character is a capital or if the second character isn't a capital - not just when both are done wrong.

Hope it helps!

ms2030
ms2030
2,973 Points

Thanks!

private char validateGuess(char letter) {
    if (!Character.isLetter(letter)) {
      throw new IllegalArgumentException("A letter is required."
    }
    letter = Character.toLowerCase(letter);
    if (mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >= 0) { 
      throw new IllegalArgumentException(letter + " has already been guessed")           }
    return letter;
  }
  • The above code is the example to follow.
  • We care about charAt for this challenge, rather than indexOf
  • In pseudocode, we want to check for the following condition, and throw an error: " if the character at index 0 of fieldName does not equal 'm' OR the character at index 1 of fieldName is not upper case"