R: Stop Function Execution

stop {base} | R Documentation

## Stop Function Execution

### Description

`stop` stops execution of the current expression, prints the message given as its argument, then executes an error action.

`geterrmessage` gives the last error message.

### Usage

    stop(message = NULL, call. = TRUE)
    geterrmessage()

### Arguments

`message` | a character vector (of length 1) or `NULL`.
`call.` | logical, indicating if the call should become part of the error message.

### Details

The error action is controlled by the current error handler set by `options(error=)`. The default behaviour (the `NULL` error-handler) in interactive use is to return to the top level prompt, and in non-interactive use to (effectively) call `q("no", status=1, runLast=FALSE`).

### Value

`geterrmessage` gives the last error message, as character string ending in `"\n"`.

### See Also

`warning`, `restart` to catch errors and retry, and `options` for setting error handlers. `stopifnot` for validity testing.

### Examples

    options(error = expression(NULL))# don't stop on stop(.)  << Use with CARE! >>

    iter <- 12
    if(iter > 10) stop("too many iterations")

    tst1 <- function(...) stop("dummy error")
    tst1(1:10,long,calling,expression)

    tst2 <- function(...) stop("dummy error", call. = FALSE)
    tst2(1:10,long,calling,expression,but.not.seen.in.Error)

    options(error = NULL)# revert to default

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