Checklist or general directions on how to write a good CR-ish answer

Question

This question is intended to be the counterpart of Checklist for how to write a good Code Review question.

Getting started with Code Review:

New users often seem to have problems to understand, what exactly is expected from a CR-Answer. Many come from Stack Overflow, others maybe from Software Engineering.

These sites favor a different kind of answer than Code Review. I'd suggest providing a guideline or even checklist for new users on how we like our answers best ;)

Some of the most common "mistakes" that new users make:

1. SO-ish flavoring: alternative code (mostly without explanation)
2. Software Engineering flavoring: much much explanation, but missing relation to the code at hand.
3. Trying to go over every Issue in code and then resign over the sheer amount. --> no answer posted
4. Only "reviewing" the algorithm and not the style (probably also coming from SO), and not posting an answer, because no optimization can be found :(

There already has been a question on what makes a good answer. There was only one answer to that. The problem I have with that answer is, that it only states what a good answer has and not how to write an answer so it becomes good ;)

Answer 1

There's a few things you might want to follow when reviewing code:

• Understand the asker's level of expertise:
  Some answers here on codereview are really in-depth. They address issues, that only experts could find, sometimes in ways, that only experts understand. While these answers are awesome, they won't help a complete newbie understand anything.
  Keep in mind, that OP is possibly not as knowledgeable as you, and tailor your answer to their level of expertise.

• Be a nice reviewer:
  Getting one's code reviewed is ... difficult to start. After all it's your code. You invested (sometimes very much) time and emotions into it. And then there's this ... on the internet saying my code is [swearword here]. How dare he! To prevent OP feeling offended by your answer, you should always be aware about this.
  There's some nice answers explaining a bit more in detail at: How can I be a nice reviewer?

• Short answers are okay:
  You can find more information in Short answers and code-only answers , but the bottom line is: If your answer can stand on your own, and reviews the code, why not post it? Even multiple answers are okay, as long as each is justified on it's own. Additionally some questions just contain code so extremely bad, that:

  Nobody could catch everything and retain their sanity, simultaneously, with that bad of code

  as Phrancis puts it in Chat, sometimes code just needs a second or third review, simply because of the sheer amount of issues present.

• Avoid stating absolutes:
  "Your indentation is wrong" doesn't help anyone. It's often better to say something like: "Your indentation is not conform with the [...] standards. These are defined in [link]. You should change your indentation to [...] per level."
  This goes for all stylistic advice, and sometimes even for algorithmic advice.