R in a Nutshell, 2nd Edition

Expressions

R code is composed of a series of expressions. Examples of expressions in R include assignment statements, conditional statements, and arithmetic expressions. Here are a few examples of expressions:

> x <- 1
> if (1 > 2) "yes" else "no"
[1] "no"
> 127 %% 10
[1] 7

Expressions are composed of objects and functions. You may separate expressions with new lines or with semicolons. For example, here is a series of expressions separated by semicolons:

> "this expression will be printed"; 7 + 13; exp(0+1i*pi)
[1] "this expression will be printed"
[1] 20
[1] -1+0i