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Java Java Objects (Retired) Delivering the MVP Validation

Jason Holt
Jason Holt
10,041 Points

Checking Characters Case Java

Can't get this working. Don't know what I am missing. How do I check the characters in this string to see if they are a letter AND are uppercase? How can I do this with any length string? I'm lost here.

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
      if (fieldName.charAt(0) != 'm') {
            throw new IllegalArgumentException("The first letter m is required");
        } 

    if (Character.isLetter(fieldName.charAt(1)) == true && Character.isUpperCase(fieldName.charAt(1)) == false) {
    throw new IllegalArgumentException("Capital Letter Needed");
    } else if (Character.isLetter(fieldName.charAt(2)) == true && Character.isUpperCase(fieldName.charAt(2)) == false) {
    throw new IllegalArgumentException("Capital Letter Needed");
    }

    return fieldName;
  }

}

1 Answer

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher

See (Character.isUpperCase)[http://docs.oracle.com/javase/7/docs/api/java/lang/Character.html#isUpperCase(char)]

Let me know if you don't get it from there!

Hope it helps!

Jason Holt
Jason Holt
10,041 Points

Whoah... well I tried this: if(Character.isUpperCase(fieldName.charAt(1)) == false { exception code here } and it worked... but it doesn't check for camel case on a third character (index 2)?