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Java Java Objects (Retired) Delivering the MVP Validation

Jian Chen
Jian Chen
4,938 Points
Posted by Jian Chen
Jian Chen
4,938 Points

How do I check if input String has something in it that isn't a letter?

I have this and it said Bummer! Expected "m_first_name" to fail but it passed.

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("must be m");
    }
    Character.toUpperCase(fieldName.charAt(1));
    return fieldName;
  }

}

1 Answer

James Simshaw
James Simshaw
28,738 Points

Hello,

You almost have this one. You just need to check if the second character follows camel casing and is an upper case character in addition to the first letter being an m. If it isn't an upper case character, then you would also want to throw the IllegalArgumentException. My hint for this would be to check out static methods in the Character wrapper class. Documentation for it can be found at http://docs.oracle.com/javase/8/docs/api/java/lang/Character.html

James Simshaw
James Simshaw
28,738 Points

You're welcome, good luck with the rest of the challenges and courses.