R: Combine multiple words into a single string

combine_words {knitr} | R Documentation

## Combine multiple words into a single string

### Description

When a value from an inline R expression is a character vector of multiple elements, we may want to combine them into a phrase like a and b, or `a, b, and c`. That is what this a helper function does.

### Usage

    combine_words(words, sep = ", ", and = " and ", before = "", after = before)

### Arguments

`words` | A character vector.
`sep` | Separator to be inserted between words.
`and` | Character string to be prepended to the last word.
`before, after` | A character string to be added before/after each word.

### Details

If the length of the input `words` is smaller than or equal to 1, `words` is returned. When `words` is of length 2, the first word and second word are combined using the `and` string. When the length is greater than 2, `sep` is used to separate all words, and the `and` string is prepended to the last word.

### Value

A character string.

### Examples

    combine_words("a")
    combine_words(c("a", "b"))
    combine_words(c("a", "b", "c"))
    combine_words(c("a", "b", "c"), sep = " / ", and = "")
    combine_words(c("a", "b", "c"), and = "")
    combine_words(c("a", "b", "c"), before = "\"", after = "\"")

[Package knitr version 1.20 Index]