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Java Java Objects (Retired) Delivering the MVP Validation

Albert Reel
Albert Reel
5,555 Points

Delivering the MVP and stumped.

Can someone point me towards the source of my errors. I was trying to isolate the target char from the beginning of the input string and I keep running into syntax errors.

Anyone have a fresh look at this?

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

    char mFirstLetter = valueOf(fieldName.CharAt(0));
    char mSecondLetter = valueOf(fieldName.CharAt(1));

    while (mFirstLetter != 'm') {
      throw new IllegalArguementException ("Field must start with m");
    }

    while (! mSecondLetter.isUppercase) {
      throw new IllegalArguementException ("Please use CamelCase");
    }

    return fieldName;
  }

}

2 Answers

Stephen Bone
Stephen Bone
12,359 Points

Hi Albert

There were a few issues mainly syntax errors. I've updated your code to reflect the changes and annotated it as best as I can remember ;)

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

    // removed the valueOf method as it was unnecessary
    // should be a lowercase 'c' for charAt method
    char mFirstLetter = fieldName.charAt(0);
    char mSecondLetter = fieldName.charAt(1);

    while (mFirstLetter != 'm') {
      // removed an 'e' in the spelling of argument
      throw new IllegalArgumentException ("Field must start with m");
    }
    // need to call the isUpperCase static method directly from the Character class
    // missing a capital 'C' in isUpperCase method
    while (! Character.isUpperCase(mSecondLetter)) {
      throw new IllegalArgumentException ("Please use CamelCase");
    }

    return fieldName;
  }

}

Hope it helps!

Stephen

Albert Reel
Albert Reel
5,555 Points

Im embarrassed how many times I read over those mistakes. This makes a lot more sense. Thank you.

Stephen Bone
Stephen Bone
12,359 Points

No worries, we all experience moments when we just can't see the error! Glad I could help.

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.

  • 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"

public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {
    if (fieldName.charAt(0) != 'm' || !Character.isUpperCase(fieldName.charAt(1))) {
      throw new IllegalArgumentException("The field name does not match the style");
    }
    return fieldName;
  }

}