R help - Apr 2008 - How to test if t[["cat"]] exists ?

Hi,
> t <- list("cat"=1)
> exists("t")
[1] TRUE
> exists("t[["cat"]]")
Error: unexpected symbol in
"exists("t[["cat"
> exists("t[[\"cat\"]]")
[1] FALSE

Thanks
Stanley

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On Apr 15, 2008, at 9:53 PM, Ng Stanley wrote:
> Hi,
>
>> t <- list("cat"=1)
>> exists("t")
> [1] TRUE
>> exists("t[["cat"]]")
> Error: unexpected symbol in "exists("t[["cat"
>> exists("t[[\"cat\"]]")
> [1] FALSE
Perhaps what you want is:

"cat" %in% names(t)
> Thanks
> Stanley
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College