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Java Java Objects (Retired) Delivering the MVP Validation

Michael LaCroix
Michael LaCroix
5,828 Points
Posted by Michael LaCroix
Michael LaCroix
5,828 Points

Can't figure out how to verify capitalization

I'm stuck on how to verify if the second letter of the member variable is capitalized. I've tried a number of things.

fieldName.isUpperCase != charAt(1) fieldName.charAt(1) != isUpperCase !fieldName.isUppercase(charAt(1))

None of these worked and I'm stuck. Would love a thought on why any or all of the above didn't work. Thanks.

TeacherAssistant.java 
public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {
        if (fieldName.charAt(0) != 'm' || fieldName.charAt(1) != isUpperCase) {
        throw new IllegalArgumentException("Field must begin with 'm' and second letter must be capitalized.");
    }
    // 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;
  }

}

5 Answers

Stephen Bone
Stephen Bone
12,359 Points
Stephen Bone
Stephen Bone
12,359 Points

Hi Michael

I don't know if you've managed to figure this out or not but to build on what Logan has suggested.

isUpperCase and isLowerCase are static methods which means you must call them directly from the class. In this case these methods are called from the Character class, like so Character.isUpperCase(). Then you need to pass in the Char you want to test which we can do using the charAt() method of the fieldName String as we've been doing previously.

The code will look something like below:

Remember if we test for upper case we may need to specify a '!' to change the statement to not upper case

if (fieldName.charAt(0) != 'm' || ! Character.isUpperCase(fieldName.charAt(1))) {

Hope it helps!

Stephen

Logan R
Logan R
22,989 Points
Logan R
Logan R
22,989 Points

You can use the Character class.

Character.isUppercase(CHAR);
Michael LaCroix
Michael LaCroix
5,828 Points
Michael LaCroix
Michael LaCroix
5,828 Points

Thanks, but I know to use the character class. That's exactly what I'm already trying to do. I can't figure out how to single out the second variable.

"2. The second letter in the field name must be uppercased to ensure camel-casing"

The closet I think I came was this: fieldName.charAt(1) != isUpperCase but that didn't work.

Michael LaCroix
Michael LaCroix
5,828 Points
Michael LaCroix
Michael LaCroix
5,828 Points

Also tried fieldName.isLowerCase(charAt(1)) and that didn't work either.

Michael LaCroix
Michael LaCroix
5,828 Points
Michael LaCroix
Michael LaCroix
5,828 Points

Thanks Steve. I reposted and got almost the exact advice you gave.