Question

let’s define the following string s:

s <- "$ A; B; C;"

I need to translate s into:

"$ A; $B; $C;"

the semicolon is the separator. However, $ is only one of 3 special characters which can appear in the string. The data frame m holds all 3 special characters:

m <- data.frame(sp = c("$", "%", "&"))

I first used strsplit to split the string using the semicolon as the separator

> strsplit(s, ";")
[[1]]
[1] "$ A" " B"  " C" 

I think the next step would be to use grep or match to check if the first string contains any of the 3 special characters defined in data frame m. If so, maybe use gsub to insert the matched special character into the remaining sub strings. Then simple use paste with collapse = “” to merge the substrings together again. Does that make sense?

Cheers

Answer 1

What about something like this:

getmeout = gsub("[$|%|& ]", "", unlist(strsplit(s, ";")))
whatspecial = unique(gsub("[^$|%|&]", "", s))
whatspecial
# [1] "$"
getmeout
# [1] "A" "B" "C"
paste0(whatspecial, getmeout, sep=";", collapse="")
# [1] "$A;$B;$C;"