Bypassing an error inside a loop in R

I have a dummy script below:

a <- 1
b <- 2
c <- 3
e <- 5

list <- letters[1:5]

for (loop in (1:length(list)))
    {print(paste(list[loop],get(list[loop]),sep="-"))
    }

> source('~/.active-rstudio-document')
[1] "开发者_Python百科a-1"
[1] "b-2"
[1] "c-3"
Error in get(list[loop]) : object 'd' not found

Currently I have a problem that since d is not present, so an error message pop up and block the processing of e.

I wonder if R has some kind of "error handling", that is to bypass the error due to d, keep processing e, then return the error message when all valid data are processed.

Thanks.

---

Use exists to check whether a variable exists:

for (loop in (1:length(list))){
  if(exists(list[loop])){
    print(
        paste(list[loop], get(list[loop]), sep="-"))
  }
}

[1] "a-1"
[1] "b-2"
[1] "c-3"
[1] "e-5"

More generally, R has a sophisticated mechanism for catching and dealing with errors. See ?tryCatch and its simplified wrapper, ?try, for more details.

---

Yes, as in most developed languages, there is such a mechanism. Check ?try.