Self-tutoring about servlets: the tutor mentions an observation. If there’s the slightest mistake in the web.xml file (tomcat server), you might discover that not only the servlets don’t work, but the tomcat server won’t serve anything at all, not even …
Self-tutoring about Java: the tutor mentions classpath. It might properly be called CLASSPATH. It’s where Java will search for the class you want it to run. Yet, if you’re running a Java program from the command line after compiling it, …
Self-tutoring about Java: the tutor mentions a couple of ideas about Java abstract classes. There are numerous Java versions out there, not all of which necessarily agree on everything. Herein I’m sharing my own experience. In Java, an abstract class …
Tutoring comp sci, you experiment a lot. The tutor shares one. The java command, in Windows, anyway, seems to like a space between the directory and the filename you are running. java -cp f:/dir1/dir2 program_file not java -cp f:/dir1/dir2/program_file Source: …
Tutoring Java programming, you might be asked to clarify about overriding. The tutor shares some thoughts. In Java, when you override a method, you either define its performance (give it a “body”), or else redefine (change) its performance . Case …
Java: overriding methods: what it means, and rules about it Read more →
Tutoring Java programming, this error message might come up. The tutor talks about a couple of its causes. The message error: non-static method MethodX() cannot be referenced from a static context has a couple of causes I know: The class …
Tutoring Java programming, there are so many interesting facets to encounter. The tutor talks about a constructor of a subclass and the word super. Let’s imagine you write a subclass. Furthermore, let’s imagine the parent class (the superclass) has a …
The tutor offers an interpretation of what the asterisk (aka, wildcard) means in an import statement. I’m not trained in Java, but do write experimental programs with it. Here are some ideas about the import statement, as I understand it: …
The tutor comments on JavaScript null and undefined. Null, it seems, is often mentioned in computer science. Perhaps it’s used a little loosely: it might refer to the value read when there’s nothing there, or the value of a variable …
Computer science: JavaScript: null value, undefined type and value Read more →
The tutor brings up a couple of “emergency procedures” for stopping a program. I don’t write many big programs; rather, I’ll often write a page or so of code (with lots of white space) to test a utility from a …
Comp Sci: command prompt testing (Windows 7): how to kill a runaway program Read more →