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Java Java Objects (Retired) Delivering the MVP Validation

Posted by Adiv Abramson
Adiv Abramson
6,919 Points

If validatedFieldName() throws an exception, doesn't "throws <type>Exception" need to be in its signature?

In the exercise, the validatedFieldName() method will throw an IllegalArgumentException when the fieldName parameter doesn't begin with "m" followed by an uppercase letter. I thought that methods that throw exceptions must have a signature which includes a list of the exceptions thrown, e.g.

public void myMethod() throws IllegalArgumentException { //code if (<test>) { throw new IllegalArgumentException("Invalid parameter."); } }//myMethod()

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
    return fieldName;
  }

}

1 Answer

Dan Johnson
Dan Johnson
40,533 Points
Dan Johnson
Dan Johnson
40,533 Points

Since IllegalArgumentException is an unchecked exception (it extends RuntimeException) you're not required to add the throws clause or use a try-catch block.