如何检查对象(变量)是否定义在 r？

Question

I'd like to check if some variable is defined in R - without getting an error. How can I do this?

My attempts (not successful):

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

Thanks!

转载于:https://stackoverflow.com/questions/9368900/how-to-check-if-object-variable-is-defined-in-r

Answer 1

You want exists():

R> exists("somethingUnknown")
[1] FALSE
R> somethingUnknown <- 42
R> exists("somethingUnknown")
[1] TRUE
R>