How to replace a symbol by a backslash in R?

Question

Could you help me to replace a char by a backslash in R? My trial:

gsub("D","\\","1D2")

Thanks in advance

Answer 1

You need to re-escape the backslash because it needs to be escaped once as part of a normal R string (hence '\\' instead of '\'), and in addition it’s handled differently by gsub in a replacement pattern, so it needs to be escaped again. The following works:

gsub('D', '\\\\', '1D2')
# "1\\2"

The reason the result looks different from the desired output is that R doesn’t actually print the result, it prints an interpretable R string (note the surrounding quotation marks!). But if you use cat or message it’s printed correctly:

cat(gsub('D', '\\\\', '1D2'), '\n')
# 1\2