Extract characters that differ between two strings

Question

I have used adist to calculate the number of characters that differ between two strings:

a <- \"Happy day\"
b <- \"Tappy Pay\"
adist(a,b)          


        

Answer 1

The following function could be a better option to solve problem like this.

list.string.diff <- function(a, b, exclude = c("-", "?"), ignore.case = TRUE, show.excluded = FALSE)
{
if(nchar(a)!=nchar(b)) stop("Lengths of input strings differ. Please check your input.")
if(ignore.case)
{
a <- toupper(a)
b <- toupper(b)
}
split_seqs <- strsplit(c(a, b), split = "")
only.diff <- (split_seqs[[1]] != split_seqs[[2]])
only.diff[
(split_seqs[[1]] %in% exclude) |
(split_seqs[[2]] %in% exclude)
] <- NA
diff.info<-data.frame(which(is.na(only.diff)|only.diff),
split_seqs[[1]][only.diff],split_seqs[[2]][only.diff])
names(diff.info)<-c("position","poly.seq.a","poly.seq.b")
if(!show.excluded) diff.info<-na.omit(diff.info)
diff.info

from https://www.r-bloggers.com/extract-different-characters-between-two-strings-of-equal-length/

Then you can run

list.string.diff(a, b)

to get the difference.