Lab Exercise 3: Generating Semantic Errors

Recall that semantic errors cannot be detected by the compiler. They are errors in the logic of the program that cause it to do something it is not really supposed to do. For each of the following errors, try to think about what will happen before you run the program. Then try to describe the logic error being committed. Ask yourself what kind of test you might perform to detect the error (if you didn't already know where it was).

• Button, button, who's got the button? Comment out the line (by beginning it with double slashes) that contains the add(clickMe); statement. This is a pretty easy error to detect.

• What's the difference? Put a space before the exclamation point in ``Click Me!'' in the actionPerformed() method. This error is a little more subtle than the first one. How would you detect this error?

That's enough! Feel free to make up your own experiments and play around some more with the program.