Double null check in single line

Question

Is the following code the best way to check for null for two times in a single line for initializaing a final variable?

final String textValue = text != null ? text.getText() != null ? text.getText() : "" : "";

Answer 1

Well I'd probably use a single conditional with an && condition instead:

final String textValue = text != null && text.getText() != null ? text.getText()
                                                                : "";

If you find you need to do this in more than one place, you may well want to wrap it in a method:

// We don't know what the type of text is here... adjust appropriately.
public static String getTextOrDefault(TextBox text, String defaultValue)
{
    return text != null && text.getText() != null ? text.getText()
                                                  : defaultValue;
}

Or adjusted to avoid calling getText() more than once:

// We don't know what the type of text is here... adjust appropriately.
public static String getTextOrDefault(TextBox text, String defaultValue)
{
    if (text == null)
    {
        return defaultValue;
    }
    String textValue = text.getText();
    return textValue != null ? text.getText() : defaultValue;
}

Then you can simplify your variable declaration:

final String textValue = SomeHelper.getTextOrDefault(text, "");

Note that whether calling text.getText() more than once is a problem depends on your scenario - in some cases it would be a bad idea, and you should restructure your code to avoid it. We can't tell for sure, but it's worth considering.