Cisco 200-901 Actual Questions

Refactoring is done during test-driven development (TDD) to improve the maintainability and readability of the code. After writing tests and ensuring that the code passes those tests, developers refactor to clean up the code, making it more efficient and easier to understand without changing its functionality.

A. to enable larger objects and longer methods - Incorrect. Refactoring aims to simplify and streamline code, not make it larger or more complex. B. to improve maintainability and readability - Correct. Refactoring makes the code easier to maintain and understand. C. to ensure that the previous uses of the objects are explained - Incorrect. This is not the purpose of refactoring. D. to ensure the duplication of essential code - Incorrect. Refactoring seeks to reduce code duplication, not ensure it.

References:

Test-Driven Development by Example

In the provided sequence diagram, each call must complete before the next one can proceed, indicating that the calls are synchronous. Synchronous calls block further execution until the response is received, maintaining a sequential order of operations.

Synchronous Nature: The diagram shows each function call being made and then waiting for a callback before proceeding to the next step.

Blocking Behavior: Each interaction completes fully before the next one starts, which is characteristic of synchronous operations.

Option C correctly identifies that all the calls shown in the sequence diagram are synchronous.

To create and switch to a new branch called "my-bug-fix" in Git, you use the git checkout -b command. This command creates the branch and switches to it in one step.

A. git checkout -b my-bug-fix - Correct. This command creates a new branch and switches to it. B. git branch -b my-bug-fix - Incorrect. The -b option is not valid with git branch. C. git branch my-bug-fix - This creates a new branch but does not switch to it. D. git checkout my-bug-fix - This switches to an existing branch but does not create a new one.

References:

Git Branching - Creating a Branch

A VLAN (Virtual Local Area Network) allows devices on one or more LANs to be grouped together as if they were on the same physical network, even if they are not.

Logical Segmentation: VLANs provide logical segmentation of networks, enabling devices to communicate as if they are on the same physical network.

Isolation and Flexibility: They offer isolation and flexibility in network design, improving security and reducing broadcast domains.

Option B is correct as VLANs create logical groupings of devices that communicate as if they are on the same physical LAN.