Functions overview

function_name = function(arg1, arg2, arg3) {
     # commands
     return(someReturnValue)
}

• Function parameter names are local to the function

• variables created in the function are local

• Result of last expression returned implicitely (even without calling return())

• When accepting a vector of numbers what if the user sends in a vector of strings (different class of data)?

• What if some of the values are missing? (NA)

• What if the vector is empty?