CS210 Lab: Introduction to Visual C++--Debugger Tips

In this lab example, we used the Step Over to examine the loop.  What will happen if we use Step In? Well, Step In will examine the program one line a time and it will go into every function if a function is called.  Therefore, if we use Step In to examine the loop with the cout and cin statements, we would have stepped into the  cout and cin system functions. this is not what we want. So when you debug your program, whenever you encounter the system functions, which do not need to be debugged, use Step Over instead of Step In. 

This is one of the tricky part of the debugging process which could get you into trouble.  You will get into even more troubles if you do not know what you are doing.  The following are some surprises, how they happened, and how to deal with them.

• Problem one: The console window disappears quickly after it appears.  
• The window is still there. You'll find it from the bottom of your desktop.


• Problem two:  A "Find File" dialog box pops up.  
• You probably pressed Step Into when you should have pressed over , and you entered some function you didn't expect (such as a predefined library function). This might happen especially if you press Step Into when the arrow points to an input or output statement (the << and >> operators are actually predefined functions). (It can also happen if you press Step Over  beyond the point where your program ends.) VC++ is asking for a file containing the source code for this function. Select Debug --> Step Out) to finish executing the library function and get execution back to your source code.


• Problem three:  My source code has been replaced with weird stuff, with numbers in the left-hand column and words like "push" and "mov."  
• This happens for the same reasons as above: you probably entered a library function with (should have used ). This is the assembly code version of the function. Select File | Close to get back to your source code window,  then press to finish executing the library function and get execution back to your source code.

If all else fails, you can always select Debug --> Restart to start your program over again, or select Debug --> Stop Debugging to quit execution of your program and stop debugging altogether.