decision table testing from code code example

Example: decision table testing

The decision table is a software testing
type for testing the system behavior for 
different input combinations. 
It provides complete coverage of test cases
and helps to reduce the rework on writing 
test scenarios & test cases.
We are also guaranteing that we consider
every possible combination of the test.
FOR EXAMPLE = Lets say we are writing
test case for login functionality.
We need to try different inputs like
lets say:
Case 1 –
Username and password both were wrong.
The user is shown an error message.

Case 2 –
Username was correct, but the password was wrong.
The user is shown an error message.

Case 3 –
Username was wrong, but the password was correct.
The user is shown an error message.

Case 4 – 
Username and password both were correct,
and the user is navigated to the homepage.