Bug in Validation Challenge!

This code, alone, passes the test:<br>

if ((fieldName.charAt(0) == 'm') && Character.isUpperCase(fieldName.charAt(1))){ return fieldName; }else{ throw new IllegalArgumentException ("This does not work"); }

in the case of fieldName.charAt(1) when fieldName = "m_first_name", it is failing because the test for uppercase and lower case on an underscore is a fail. It's not failing because the 'f' is lower cased. <br> <br>

The way to test it is to change the code to" !Character.isLowerCase(fieldName.charAt(1)))" as this would turn the false into a true and incorrectly pass the "m_first_name" field name.

Here's my full code to test this...

public class TeacherAssistant {

 public static void main(String[] args){
    System.out.println ( validatedFieldName("m_First_name"));
    System.out.println ( validatedFieldName("m__First_name"));
    System.out.println ( validatedFieldName("m_______First_name"));
    System.out.println ( validatedFieldName("m_______first_name"));
}

public static int findSecondLetter(String fieldName) { int location = 1; boolean isLetter = false; while (!isLetter) { if (Character.isLetter(fieldName.charAt(location))){ isLetter = true; } else { location +=1; isLetter=false; } } return location;

}

public static String validatedFieldName(String fieldName) { char letter1 = fieldName.charAt(0); char letter2 = fieldName.charAt(findSecondLetter(fieldName));

if (!(letter1 =='m') || Character.isLowerCase(letter2)) {
 throw new IllegalArgumentException ("This does not work"); 
}
// 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
return fieldName;

}

}

apologies for the awful formatting... again, posting code is a bit of a challenge for me :-(

Sorry Craig, I may have misunderstood your response. I took a bit of a literal interpretation on the test in reading that the test must pass if the second letter is upper cased. The solution isUppercase() does the job in passing the test, however taking an alternative route of !isLowercase() would fail the test because it would turn an underscore character into a "true" in the same way an upper case character would. When your test of "m_first_name" incorrectly passed the test, i thought that your intention was to be able to capture the second real letter rather than fail "all other" characters vs an upper cased letter. Hopefully that makes sense. Thanks for your response!

Oh...hmmm...sorry no I meant 2nd character. I can update that text. Sorry for the confusion!

It's not a problem, it was a great learning moment. I just wanted to bring that nuance up in case that was the intent. Thank you for making the course, it's been great to work on!

public static int findSecondLetter(String fieldName) { <br> int location = 1; <br> boolean isLetter = false; <br> while (!isLetter) { <br> if (Character.isLetter(fieldName.charAt(location))){ <br> isLetter = true; <br> } else { <br> location +=1; <br> isLetter=false; <br> } <br> }<br> return location; <br> } <br> <br>

forgive the terrible formatting.. I can't figure out how to post this as code... But that finds the second letter.

Okay so to add code, just use ``` at start & end (TIL).

Thanks for the write up bud.

public static int findSecondLetter(String fieldName) { int location = 1; 
 boolean isLetter = false; 
 while (!isLetter) { 
 if (Character.isLetter(fieldName.charAt(location))){ 
 isLetter = true; 
 } else { 
 location +=1; 
 isLetter=false; 
 } 
 }
 return location; 
 }