Process to pass from problem to code. How did you learn?

by

I go via the test-driven approach.

1. I write down (on paper or plain text editor) a list of tests or specification that would satisfy the needs of the problem.

- simple calculations (no discounts and concessions) with:
    - single item
    - two items
    - maximum number of items that doesn't have a discount
- calculate for discounts based on number of items
    - buying 10 items gives you a 5% discount
    - buying 15 items gives you a 7% discount
    - etc.
- calculate based on hourly rates
    - calculate morning rates
    - calculate afternoon rates
    - calculate evening rates
    - calculate midnight rates
- calculate based on buyer's age
    - children
    - adults
    - seniors
- calculate based on combinations
    - buying 10 items in the afternoon

2. Look for the items that I think would be the easiest to implement and write a test for it. E.g single items looks easy

The sample using Nunit and C#.

[Test] public void SingleItems()
{
    Assert.AreEqual(5, GetPrice(5, 1));
}

Implement that using:

public decimal GetPrice(decimal amount, int quantity)
{
    return amount * quantity; // easy!
}

Then move on to the two items.

[Test]
public void TwoItemsItems()
{
    Assert.AreEqual(10, GetPrice(5, 2));
}

The implementation still passes the test so move on to the next test.

3. Be always on the lookout for duplication and remove it. You are done when all the tests pass and you can no longer think of any test.

This doesn’t guarantee that you will create the most efficient algorithm, but as long as you know what to test for and it all passes, it will guarantee that you are getting the right answers.

More Related Contents:

  1. Is process in VHDL reentrant?
  2. 127 Return code from $?
  3. How do I read the output of a child process without blocking in Rust?
  4. How to capture the PID of a process when launching it from command line?
  5. How to start a background process in Python?
  6. How to get a list of current open windows/process with Java?
  7. What are the differences between the threading and multiprocessing modules?
  8. Executing a Java application in a separate process
  9. List running processes on 64-bit Windows
  10. How to stop java process gracefully?
  11. How to get PID of process I’ve just started within java program?
  12. How to detect win32 process creation/termination in c++
  13. How does Ctrl-C terminate a child process?
  14. What resources are shared between threads?
  15. get process name from process id (win32)
  16. How can I kill task manager processes through VBA code?
  17. Kill a Process by Looking up the Port being used by it from a .BAT
  18. android finish() method doesn’t clear app from memory
  19. How to remote invoke another process method from C# application
  20. List AppDomains in Process
  21. Linux/Unix command to determine if process is running?
  22. check if some exe program is running on the windows
  23. How to get child process from parent process
  24. Difference between user-level and kernel-supported threads?
  25. Terminate a process tree (C for Windows)
  26. How do I attach Visual Studio to a process that is not started yet?
  27. How to get the current ProcessID?
  28. kill process with python
  29. Visual Basic Capture output of cmd
  30. Runtime.getRuntime().exec(cmd) hanging

Leave a Comment