Testing and Running a Solution Key Points
Types of Programming Error
Syntax Error – This is where a statement written breaks the rules of the programming language. It can not be understood by the computer.
Logic Error – This is where there is a mistake in the algorithm that results in the program doing something other than what is intended to do.
Run-time Error – This is an error which occurs due to an unexpected situation with the data being processed or another external factor. The program would other wise work under normal conditions.
Testing Strategies
Testing refers to all the ways in which the programmer ensures there are no errors in the program.
Black box testing – techniques only concerned with inputs and outputs of the program, and not how it works. Valid, invalid and borderline data must be checked for.
White box testing – these are techniques that test the algorithm of the code, to make sure that all the parts function as intended.
Alpha testing – when the software is nearly complete and is being tested as a whole, by professionals who use it like an end user would.
Beta testing – takes place after alpha, where it is released to potential users outside the company.
Acceptance testing – just to demonstrate to the end user that the program works and does it's job.
Debugging Tools
Most programming languages provide facilities for finding and resolving bugs in the code. Including:
Translator diagnostics – messages generated by the translator while it is translating the source code into object code.
Break points can be used to step through the code, through stopping it running when it gets to that line. They are also useful for carrying out variable checks.
Dry runs – to locate the cause of an error, the programmer may go through it manually. This may be carried out using a trace table to record any results.
Installation and Execution
The functions carried out by the installation routine are:
Copy the executable program
Copy and prepare any datafiles needed by the program
Copy any library files that the program needs and register them on the users computer if necessary
Make the program easy to access by setting up icons, menu buttons and short cuts.
Initial configuration of the user preferences