Final answer:
A stub is a partially defined and temporary placeholder used during the development process until the actual code is written. It is not fully implemented or tested.
Step-by-step explanation:
A stub is a function that is partially defined and not fully implemented or tested. It is used as a placeholder during the development process until the actual code is written. A stub can be used to simulate certain behaviors of a function or to test other parts of the code without relying on the complete implementation of the function.
For example, let's say you're building a software application, and you have a function called 'calculateTotal' that is responsible for calculating the total cost of a purchase. However, the function is not yet implemented. You can create a stub for 'calculateTotal' that returns a fixed value, such as 100, just to test other parts of the application that depend on it. Once the actual 'calculateTotal' function is implemented and tested, the stub can be replaced.
Therefore, the statement 'A stub is a function that is completely defined and well tested' is False. A stub is a partially defined and temporary placeholder, not a complete and well-tested function.