What makes your code clean ?

Question

What are the things that make your code clean ?

Answer 1

Indentations, whitespaces, newlines. Non-scattered variable declarations. Well-formatted comments. Descriptive variable names.

Answer 2

I guess the answer is very complicated. Readability is a good start, but it's a lot more than that.
You should always consider strange input and how to handle that.
Listen to people what had happened using your code.
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The biggest problem about clean code is that everyone thinks slightly different about and you have to find out what is best for you and the people you have to work togethet.