Extracting unique numbers from string in R

Question

I have a list of strings which contain random characters such as:

list=list()
list[1] = \"djud7+dg[a]hs667\"
list[2] = \"7fd*hac11(5)\"
list[3] = \"2tu,g7gka         


        

Answer 1

Use strsplit using pattern as the inverse of numeric digits: 0-9

For the example you have provided, do this:

tmp <- sapply(list, function (k) strsplit(k, "[^0-9]"))

Then simply take a union of all `sets' in the list, like so:

tmp <- Reduce(union, tmp)

Then you only have to remove the empty string.