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

A solution using stringi

 # extract the numbers:

 nums <- stri_extract_all_regex(list, "[0-9]+")

 # Make vector and get unique numbers:

 nums <- unlist(nums)
 nums <- unique(nums)

And that's your first solution

For the second solution I would use substr:

nums_first <- sapply(nums, function(x) unique(substr(x,1,1)))