Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Objects (Retired) Delivering the MVP Validation

Jiten Mistry
Jiten Mistry
4,698 Points

How do i check if a second letter in a variable is uppercase?

For an exercise i have to check if the second letter is a capital if not, throw an error. i understand how to throw the error and access the second letter, but not sure how to actually check the case of the letter.

TeacherAssistant.java
public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {
    // These things should be verified:
    // 1.  Member fields must start with an 'm'
    if(fieldName.charAt(0) != 'm' || fieldName.charAt(1) !=  ) {
      throw new IllegalArgumentException( fieldName + ": Does not 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;
  }

}

2 Answers

If you are allowed to use it, you could try using Character.isUpperCase(fieldName.charat(1))

So your code would look like this:

public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) {
    // These things should be verified:
    // 1.  Member fields must start with an 'm'
    if(fieldName.charAt(0) != 'm' || !Character.isUpperCase(fieldName.charAt(1))) {
      throw new IllegalArgumentException( fieldName + ": Does not 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;
  }

}

Anytime! Happy to help!

Thanks for giving me best answer :)