The R Project SVN R

Rev

Rev 88581 | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 88581 Rev 88869
Line 1... Line 1...
1 
% File src/library/base/man/Control.Rd
 1 
% File src/library/base/man/Control.Rd
2 
% Part of the R package, https://www.R-project.org
 2 
% Part of the R package, https://www.R-project.org
3 
% Copyright 1995-2024 R Core Team
 3 
% Copyright 1995-2025 R Core Team
4 
% Distributed under GPL 2 or later
 4 
% Distributed under GPL 2 or later
5 
 
 5 
 
6 
\name{Control}
 6 
\name{Control}
7 
\title{Control Flow}
 7 
\title{Control Flow}
8 
\alias{Control}
 8 
\alias{Control}
Line 67... Line 67...
67 
  the loop; changing it subsequently does not affect the loop.  If
 67 
  the loop; changing it subsequently does not affect the loop.  If
68 
  \code{seq} has length zero the body of the loop is skipped. Otherwise the
 68 
  \code{seq} has length zero the body of the loop is skipped. Otherwise the
69 
  variable \code{var} is assigned in turn the value of each element of
 69 
  variable \code{var} is assigned in turn the value of each element of
70 
  \code{seq}. You can assign to \code{var} within the body of the loop,
 70 
  \code{seq}. You can assign to \code{var} within the body of the loop,
71 
  but this will not affect the next iteration.  When the loop terminates,
 71 
  but this will not affect the next iteration.  When the loop terminates,
72 
  \code{var} remains as a variable containing its latest value.
 72 
  \code{var} remains as a variable containing its latest value. The
- 
 
 73 
  \code{seq} is implicitly unclassed. For classed objects, one can use
- 
 
 74 
  \code{\link{as.list}} to prepare a list to iterate over or
- 
 
 75 
  \code{\link{seq_along}} to get an index vector and then  explicitly extract
- 
 
 76 
  individual elements (see also \code{\link{lapply}}).
73 
 
 77 
 
74 
  The null coalescing operator \code{\%||\%} is a simple 1-line function:
 78 
  The null coalescing operator \code{\%||\%} is a simple 1-line function:
75 
  \code{x \%||\% y} is an idiomatic way to call
 79 
  \code{x \%||\% y} is an idiomatic way to call
76 
  \preformatted{
 80 
  \preformatted{
77 
    if (is.null(x)) y else x
 81 
    if (is.null(x)) y else x