regex - Remove trailing and leading spaces and extra internal whitespace with one gsub call -

i know can remove trailing , leading spaces

gsub("^\\s+|\\s+$", "", x)

and can remove internal spaces with

gsub("\\s+"," ",x)

i can combine these 1 function, wondering if there way 1 use of gsub function

trim <- function (x) {   x <- gsub("^\\s+|\\s+$|", "", x)   gsub("\\s+", " ", x) }  teststring<- "       test. "  trim(teststring)

here option:

gsub("^ +| +$|( ) +", "\\1", teststring)  # frank's input, , agstudy's style

we use capturing group make sure multiple internal spaces replaced single space. change " " \\s if expect non-space whitespace want remove.

Th