Outputs the objects, concatenating the representations. cat
performs much less conversion than print.
cat(… , file = "", sep = " ", fill = FALSE, labels = NULL,
append = FALSE)R objects (see ‘Details’ for the types of objects allowed).
A connection, or a character string naming the file
to print to. If "" (the default), cat prints to the
standard output connection, the console unless redirected by
sink.
If it is "|cmd", the output is piped to the command given
by cmd, by opening a pipe connection.
a character vector of strings to append after each element.
a logical or (positive) numeric controlling how the output is
broken into successive lines. If FALSE (default), only newlines
created explicitly by "\n" are printed. Otherwise, the
output is broken into lines with print width equal to the option
width if fill is TRUE, or the value of
fill if this is numeric. Non-positive fill values are
ignored, with a warning.
character vector of labels for the lines printed.
Ignored if fill is FALSE.
logical. Only used if the argument file is the
name of file (and not a connection or "|cmd").
If TRUE output will be appended to
file; otherwise, it will overwrite the contents of
file.
None (invisible NULL).
cat is useful for producing output in user-defined functions.
It converts its arguments to character vectors, concatenates
them to a single character vector, appends the given sep =
string(s) to each element and then outputs them.
No linefeeds are output unless explicitly requested by "\n"
or if generated by filling (if argument fill is TRUE or
numeric).
If file is a connection and open for writing it is written from
its current position. If it is not open, it is opened for the
duration of the call in "wt" mode and then closed again.
Currently only atomic vectors and names are handled,
together with NULL and other zero-length objects (which produce
no output). Character strings are output ‘as is’ (unlike
print.default which escapes non-printable characters and
backslash --- use encodeString if you want to output
encoded strings using cat). Other types of R object should be
converted (e.g., by as.character or format)
before being passed to cat. That includes factors, which are
output as integer vectors.
cat converts numeric/complex elements in the same way as
print (and not in the same way as as.character
which is used by the S equivalent), so options
"digits" and "scipen" are relevant. However, it uses
the minimum field width necessary for each element, rather than the
same field width for all elements.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
# NOT RUN {
iter <- stats::rpois(1, lambda = 10)
## print an informative message
cat("iteration = ", iter <- iter + 1, "\n")
## 'fill' and label lines:
cat(paste(letters, 100* 1:26), fill = TRUE, labels = paste0("{", 1:10, "}:"))
# }
Run the code above in your browser using DataLab