Validation Challenge

A couple things. You have 2 extra ending parenthesis on the fieldName.charAt(0) = 'm" parameter. When you use "and" statement in the if loop then if BOTH conditions are true, then you throw the exception as you've currently written it.

1. You want an "or" statement, so that if either condition is true (meaning either mistake in naming conventions has been made) the if loop throws the exception.
2. The exercise suggests using your nor statements. What you want to say is that if the character at the string index of zero is NOT m, then throw the exception. Currently, that's not what is says.
3. Take it easy on the parenthesis. Think of the methods inside the conditional as having them already.
4. I'm pretty sure the validateFieldName method doesn't have to be static, or viewable to other classes without reference to it's native class.

Try following that. The answer above is incorrect.

Happy coding! Nicolas

public class TeacherAssistant {

      public static String validatedFieldName(String fieldName) {

        if (fieldName.charAt(0) == 'm' && 
            !Character.isUpperCase(fieldName.charAt(1))) {
          throw new IllegalArgumentException("Invalid field name");
        } 
        return fieldName;
      }

    }

Honestly, no one told he poor guy he was using "=" instead of "=="? = sets variables == checks for object equality (use .equals(Object object) method for objects)

*I didn't read the problem, just fixed the first code to a working version and less parenthesis. But seriously, the most important error was the = which not a single person caught and then another person made the same mistake.

public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {

    if (fieldName.charAt(0) != 'm') {
      throw new IllegalArgumentException("The first letter must be m");
    }
    if(Character.toUpperCase(fieldName.charAt(1)) != fieldName.charAt(1)
       || !Character.isLetter(fieldName.charAt(1))) {
      throw new IllegalArgumentException("Second letter must be Uppercased and a letter");
    }
    return fieldName;
  }

}

My code...didn't know .isUpperCase method existed. Could be shorter, but I think it's good (for the challenge) =D

Sorry Triple Post =(

public class TeacherAssistant {

  public String validateFieldName(String fieldName) {

    if (fieldName.charAt(0) = 'm' 
    || (!Character.isUpperCase(fieldName.charAt(1))
    || (!Character.isLetter(fieldName.charAt(0))))) {
      throw new IllegalArgumentException("Invalid field name.");
    } 
    return fieldName;
  }

}

should work.