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Java Java Objects (Retired) Delivering the MVP Validation

michael figueroa
michael figueroa
5,680 Points
Posted by michael figueroa
michael figueroa
5,680 Points

how to test if second letter is uppercase

I'm not sure why my code continues to allow a lower case letter and a (_) to get through.

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
    char first = fieldName.charAt(0);
    char second = fieldName.charAt(1);
    boolean firstGood = Character.isLowerCase(first);
    boolean secondGood = (!Character.isLowerCase(second));
    boolean secondGoodChar = Character.isLetter(second);

    if(!firstGood){
      throw new IllegalArgumentException(first + " must be lower case.");
    }

    if(!secondGood && secondGoodChar ){
      throw new IllegalArgumentException(second + "must be upper case");
    }

    return fieldName;
  }

}
Simon Coates
Simon Coates
28,694 Points
Simon Coates
Simon Coates
28,694 Points

(!secondGood && secondGoodChar) will always evaluate to false when secondGoodChar is false. IE, no exception will occur if not a letter. (if i'm reading this right). You might want if(!(secondGood && secondGoodChar )){

1 Answer

Simon Coates
Simon Coates
28,694 Points
Simon Coates
Simon Coates
28,694 Points

it accepted the following:

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();
    }
    // 2.  The second letter in the field name must be uppercased to ensure camel-casing
    if(!Character.isUpperCase(fieldName.charAt(1))){
      throw new IllegalArgumentException();
    }

    // NOTE:  To check if something is not equal use the != symbol. eg: 3 != 4
    return fieldName;
  }
}

You don't seem to check for the 'm' being the first character.