R: How can I replace let's say the 5th element within a string?

Question

I would like to convert the a string like be33szfuhm100060 into BESZFUHM0060.

In order to replace the small letters with capital letters I\'ve so far used the gsub f

Answer 1

If you know what portions of the string you want based on their position(s), use substr or substring. As I mentioned in my comment, you can use toupper to coerce characters to uppercase.

paste( toupper(substr(test,1, 2)),
       toupper(substr(test,5,10)),
       substr(test,12,nchar(test)),sep="")
# [1] "BESZFUHM00060"