The line through the getElementById method may look familiar to Java developers as used to indicate a deprecated Java method. In this case, it indicates that one or more of my targeted web browsers does not support this method. The auto-completion popup clearly shows that Internet Explorer 5.5 and Internet Explorer 6 are my "targeted browsers" that do not support this particular method.
The "targeted browsers" idea is useful because there may be situations in which we have the luxury of knowing which browsers we must support or, better yet, which we don't need to support. If we don't need to support a particular browser, that is one more source of potential inconsistency we do not need to worry about.
With the targeted browsers now only including Microsoft Internet Explorer versions 7 or later, the same auto-completion for document.getElementById no longer shows the method struck out and also does not list any targeted browsers not supporting it. This is because I removed the browser versions that did not support this method from my targeted browsers. See this in the next screen snapshot.
Another example of one of these warnings follows, this time demonstrating a warning that the given function will return a value in some cases, but not in all cases.
My final example for this blog entry shows a double message with an error message about using a reserved keyword ("double") and a warning message about a declaration that doesn't do anything ("no side effects").
By the way, as you've likely heard by now, there is a NetBeans IDE 6.1 Beta Blogging Contest that ends on April 19. This blog entry has been submitted as an entry into that contest.