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Noncompliant Code Example

As shown in this example, noncompliant methods noncompliant code example, a method modifies a node if it can find it in a linked list, and does nothing if the node is not in the list. But this method gives no indication if it modified any node or not. A  method can silently corrupt the state of the object if they fail to return a value that the developer can intuitively interpret:it provides little communication describing what it did.

public void updateNode(int id, int newValue) {		
  Node current = root;
  while (current != null) {
    if (current.getId() == id) {
      current.setValue(newValue);
      break;
    }
    current = current.next;
  }
}

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This compliant solution returns the result of the operation: true for success  if it modified a node and false for failure otherwise:

public boolean updateNode(int id, int newValue) {		
  Node current = root;
  while (current != null) {
    if (current.getId() == id) {
      current.setValue(newValue);
      return true; // Node successfully updated
    }
    current = current.next;
  }
  return false;
}

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This compliant solution returns the updated Node so that the developer can simply check for a null value lest if the operation fails. Return values for methods can vary depending on the control flow or the information that the developer finds more useful.

public Node updateNode(int id, int newValue) {	
  Node current = root;
  while (current != null) {
    if (current.getId() == id) {
      current.setValue(newValue);
      return current;
    }
    current = current.next;
  }
  return null;
}

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public Node updateNode(int id, int newValue) throws NodeNotFoundException {
  Node current = root;
  while (current != null) {
    if (current.getId() == id) {
      current.setValue(newValue);
      return current;
    }
    current = current.next;
  }	
  throw new NodeNotFoundException();
}

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