gsub() function replaces all matches of a string. gsub() can also be used for Regular Expression.
gsub(pattern, replacement, x, ignore.case = FALSE, perl = FALSE, fixed = FALSE, useBytes = FALSE)
Example: eliminate space
x <- "R Tutorial"
gsub(" ","",x)
[1] "RTutorial"
Additional information about gsub() function: http://www.endmemo.com/program/R/gsub.php