Replace non-duplicate character in string

Question

HI I want to replace a forward slash by a space, but only if it appears once.

 str_replace_all( 'NOOOOO//ABCDEFGHI/asdfasd//sdkksksks', "/(?!=/)", " ")

Here I want the output to be: NOOOOO//ABCDEFGHI asdfasd//sdkksksks

Answer 1

Try the following option with sub:

input <- "NOOOOO//ABCDEFGHI/asdfasd//sdkksksks"
gsub("(?<!/)/(?!/)", " ", input, perl=TRUE)

[1] "NOOOOO//ABCDEFGHI asdfasd//sdkksksks"

The strategy here is to use the pattern (?<!/)/(?!/), which matches a single forward slash which it surrounded on both sides by anything other than another forward slash.