Check if the object variable is defined in R

Question

I want to check if some variable is already defined in R without getting an error. How to dot this?

Below is my trial, but I could not succeed in it.

> is.na(qqaaa)
Error: object 'qqaaa' not found
> is.finite(qqaaa)
Error: object 'qqaaa' not found

Thanks!

Answer 1

You can use the exists():

> exists("toFindUnknown")
[1] FALSE
> toFindUnknown <- 32
> exists("toFindUnknown")
[1] TRUE