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Java Java Objects (Retired) Delivering the MVP Validation

I've added the method validatedFieldName it will return the validated field name. If the value passed in doesn't meet th

I really don't know what I'm doing wrong so can someone please HELP !!

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' ) {
      throw new IllegalArgumentException ("error");
    }
    // 2.  The second letter in the field name must be uppercased to ensure camel-casing

       if (!Character.isUpperCase(fieldName.charAt(1))) {
         throw new IllegalArgumentException("Must be uppercase."); 
    // NOTE:  To check if something is not equal use the != symbol. eg: 3 != 4
    return fieldName;
    }

 }

1 Answer

Close. But you need throws IllegalArgumentException in the method signature. And second, you need to see if the second char is a letter:

public class TeacherAssistant {

  public static String validatedFieldName(String fieldName) throws IllegalArgumentException {
    // 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' || !Character.isLetter(fieldName.charAt(1)) || !Character.isUpperCase(fieldName.charAt(1))) {
      throw new IllegalArgumentException ("error");
    }
    return fieldName;
  }

}

Thanks!!!