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Java Java Objects (Retired) Delivering the MVP Validation

Furkan Demirkan
Furkan Demirkan
7,926 Points

Improper use of isUpperCase in the Java 'Validation' challenge. Please help!

Here is my code...

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 

  throw new IllegalArgumentException("Doesnt start with m");

char secondLetter = fieldName.charAt(1); 
if(secondLetter.isUpperCase == false){
throw new IllegalArgumentException("Non-CamelCased");
    return fieldName;


Im pretty sure I did everything else correctly, but I cant figure out how to use the 'isUpperCase'. I have found a few examples on google, but none fit my needs. Thanks in advance!

3 Answers

In java char is a primitive — it has no methods. Character is an object that has a method named "isUpperCase." One adjustment:

if (Character.isUpperCase(secondLetter) == false) {
Craig Dennis
Craig Dennis
Treehouse Teacher

Also Character.isUpperCase returns a boolean so you can negate it.

// This is more standard
if (!Character.isUpperCase(secondLetter)) {

// Than
if (Character.isUpperCase(secondLetter) == false) {

I feel so dumb, I couldn't remember how to target a specific character inside of a String... Thanks! this helped me a lot and gave me a better understanding of it all.