Question

I would like to create a function that can deal with an object that may or may not have been created yet.

At the beginning of this function, I would like to have a quick “if” statement declaring if a certain variable has been created yet. In this case, a time stamp.

TS<-date()

fun<-function(){
if(TS=="")
{print("No Time Stamp Info")}
else
{print("Time Stamp created at"); TS}
}

or alternatively

TS<-date()

fun<-function(){
if(is.character(TS))
{print("Time Stamp created at"); TS}
else
{print("No Time Stamp Info")}
}

But of course if we remove the time stamp and just have the following without first assigning any value to TS:

#TS<-date()

fun<-function(){
if(TS=="")
{print("No Time Stamp Info")}
else
{print("Time Stamp created at"); TS}
}

Than I throw an error because TS does not exist. I would like to find a way so that if there is no variable “TS” in the R workspace, I get the “No Time Stamp Info” , as opposed to an error

Is there anyway to correctly set up a function that can do this?

Answer 1

What about:

if (exists("TS")) ...

this will return TRUE if TS exists.