## 27.5 Naming Functions

20201102

Function argument names use underscore separated nouns. Whilst function argument names do not risk being confused with class hierarchies the use of period to separate the nouns has become obsolete in the tidyverse world.

Preferred

build\_cyc(num\_frames=10)

Discouraged

build\_cyc(num.frames=10)
build\_cyc(numFrames=10)

Keep variable and function names shorter but self explanatory. A long variable or function name is problematic with layout and similar names are hard to tell apart. Single letter names like x and y are often used within functions and facilitate understanding, particularly for mathematically oriented functions but should otherwise be avoided. % Andrie de Vries noted this one. l Preferred

# Perform addition.

{
return(x^2 + y^2)
}

Discouraged

# Perform addition.

}