1Z0-811 Object-Oriented Programming Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Define the interface, then create a class that implements it, then implement all abstract methods, then add extra methods, then use the class

  Why this is correct

  This is the correct order because you must first define the interface contract, then create a class that agrees to implement it, then provide concrete implementations for all abstract methods, optionally add extra methods, and finally use the class.

• ✗

  Create a class that implements the interface, then define the interface, then implement all abstract methods, then add extra methods, then use the class

  Why it's wrong here

  This is incorrect because the interface must be defined before a class can implement it; otherwise, the compiler does not know what methods are required.

• ✗

  Implement all abstract methods, then define the interface, then create a class that implements it, then add extra methods, then use the class

  Why it's wrong here

  This is incorrect because you cannot implement abstract methods without knowing the interface definition, and you need a class to provide the implementations.

• ✗

  Use the class, then define the interface, then create a class that implements it, then implement all abstract methods, then add extra methods

  Why it's wrong here

  This is incorrect because you cannot use a class before it is created and its methods are implemented; the order is completely reversed.