Readability

• Readability

  • Naming booleans

  • Method length

  • Remove Unused Code

  • Nesting

  • Naming Variables and Parameters

• Code is written for humans not compilers

  • compiler does not have to maintain the code over time - humans do.

  • Code needs to be easily understood for it to be soft

• Qualities of readable code

  • Makes crystal clear the programmer’s intent

  • Makes it easy for bugs to stand out

  • Can be easily understood and changed by other programmers

  • Creates fewer surprises and annoyances when being read

• Reduces the mental effort required to understand it and therefore be able to change it safely.

Naming booleans

• The readability of logical constructs such as an if statement can often be improved by the introduction of a well-named, intermediary variable

  ```java

  if(ageInYears==40 && isEyeColorBlue && firstName=="Julia") { // etc. }

boolean isValid=ageInYears==40 && isEyeColorBlue && firstName=="Julia"; if(isValid) {} // etc. }

```

• If the code is performing some action when something is invalid, it can make sense to rename the isXXX to isNotXXX so that the reader doesn’t have to think as much

  • ie use isNotValidPerson rather than !isValidPerson

Method length

• Methods with lots of lines of code tend to be harder to understand than methods with fewer lines of code.

• Can set a number of lines but treat it as a guide, with the full knowledge that as the number of lines increases, readability decreases.

• Some methods will be very long, ie applying business logic in usecase. But accept this to keep all logic in one place

Remove Unused Code

• Every line of code that needs to be read has a mental cost associated with it.

• IDE should help with this

• This includes commented out code

• Can always use source control to go back to it

Nesting

• Multiple levels of nested code (ifs, loops, etc.) can reduce readability.

• Can use guard clauses, or extract method to reduce nesting

Naming Variables and Parameters