# Paren: Parentheses and Braces

Description Usage Value References See Also Examples

## Description

Open parenthesis, `(`, and open brace, `{`, are `.Primitive` functions in R.

Effectively, `(` is semantically equivalent to the identity `function(x) x`, whereas `{` is slightly more interesting, see examples.

## Usage

 ```1 2 3``` ```( \dots ) { \dots } ```

## Value

For `(`, the result of evaluating the argument. This has visibility set, so will auto-print if used at top-level.

For `{`, the result of the last expression evaluated. This has the visibility of the last evaluation.

## References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

## See Also

`if`, `return`, etc for other objects used in the R language itself.

`Syntax` for operator precedence.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```f <- get("(") e <- expression(3 + 2 * 4) identical(f(e), e) do <- get("{") do(x <- 3, y <- 2*x-3, 6-x-y); x; y ## note the differences (2+3) {2+3; 4+5} (invisible(2+3)) {invisible(2+3)} ```