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Chapter 1 common mistakes

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Naming

  • Methods are verbs
  • Variables are nouns

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Bad Good

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Variables declaration

  • Do not declare all local variable at the same place
  • Declare them as close as possible to where you use them

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Bad Good

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Commit messages

  • Do not declare all local variable at the same place
  • Declare them as close as possible to where you use them

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Bad Good

https://github.com/google/eng-practices

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Reading error messages in tests

  • Tests are all about expectations and actual output
  • Error starts with expectation
  • Error ends with actual result

Expected {1,10,0} but was {1,0}

Expected “Failed calculating…”

But was “”�

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Blocks of code with comments

  • Don’t write blocks of code with comments
  • Instead, refactor it to step functions
  • Code should speak for itself

Bad

Good

https://stackoverflow.com/questions/184618/what-is-the-best-comment-in-source-code-you-have-ever-encountered

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Blobs of code or blanks. Bad

  • Some students didn’t put any blank lines
  • Some put a blank line after every line of code
  • Both choices are bad

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Good blanks

  • Tightly related code should be condense
  • Loosely related code should be separated by a blank

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No code reuse

  • In homework 5 we had to implement the following:
    • InsertAt
    • InsertFirst
    • InsertLast
  • Most people had troubles realising that InsertFirst is almost the same as InsertAt(0)
  • Don’t repeat yourself (DRY)

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Nesting

  • Some people would put a big chunk of code in if statement and another one if needed
  • However, you can work around this by returning in an inversed if

Good

Bad

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PR reviews

Bad

Good

  • Please respond :)