Often you may want to test a single piece of code. For example, say you forget how the % operator works with negative numbers, or you must determine how a certain API call operates. Writing, compiling ...

I installed java today and created the traditional hello world console application called first.java. I set the PATH stuff and whatnot, and the Sun tutorial says type in "javac first.java".

Why, of course, by virtually starting up the Java class and pushing the buttons, so to speak. You test a Java class by calling methods on it from another Java class. The following Java source file is ...