Question

Supposing I want to turn the character “6000” into an integer. I could do it with

as.integer(6000)

However, let’s say that the user input was “6***”. This gives me an error. How do I convert

as.integer(6***) 

into NA.

Answer 1

You would never write as.integer(6000) or as.integer(6***).

Instead you would write

as.integer("6***")

or even more likely

as.integer(str)

where str was some text provided by user input. Perhaps read from a file and so on.

In which case

as.integer(str)

will indeed return NA if str is a character string containing 6***.

> str = "6***"
> as.integer(str)
[1] NA
Warning message:
NAs introduced by coercion