How can two strings be concatenated?

Question

How can I concatenate (merge, combine) two values? For example I have:

tmp = cbind(\"GAD\", \"AB\")
tmp
#      [,1]  [,2]
# [1,] \"GAD\" \"AB\"

Answer 1

As others have pointed out, paste() is the way to go. But it can get annoying to have to type paste(str1, str2, str3, sep='') everytime you want the non-default separator.

You can very easily create wrapper functions that make life much simpler. For instance, if you find yourself concatenating strings with no separator really often, you can do:

p <- function(..., sep='') {
    paste(..., sep=sep, collapse=sep)
}

or if you often want to join strings from a vector (like implode() from PHP):

implode <- function(..., sep='') {
     paste(..., collapse=sep)
}

Allows you do do this:

p('a', 'b', 'c')
#[1] "abc"
vec <- c('a', 'b', 'c')
implode(vec)
#[1] "abc"
implode(vec, sep=', ')
#[1] "a, b, c"

Also, there is the built-in paste0, which does the same thing as my implode, but without allowing custom separators. It's slightly more efficient than paste().