Debugging and testing

Testing is the process of running a program with sample input data to check whether it gives the expected output and to find the presence of errors. Test data should include normal, boundary and invalid values.

Debugging is the process of locating the cause of an error found during testing (or compilation) and correcting it. Techniques include reading the compiler messages, tracing the program by hand, inserting printf statements, and using a debugger with breakpoints.

Testing finds that an error exists; debugging finds where it is and removes it.