如何在R中的字符串中查找重复元素（子字符串）

Question

a <- "ABDBBBLKDLKFFABDBOKKKMXKMABDBLPDLABDBKMKNABDBLKMXLSKMABDBOKOLKABDB"

如何查找字符串中“ ABDB”重复多少次？

Answer 1

stringi can do this very easily.

library(stringi)
stri_count_fixed(a, "ABDB")
# [1] 7

Answer 2

Here is a solution that neither requires a loop over the string nor an external package:

length(unlist(strsplit(paste0(a, "#"), "ABDB"))) - 1
#[1] 7

In this line of code, "#" is an auxiliary delimiter that is temporarily attached at the end of the string to make sure that occurrences of the pattern at the end are accounted for correctly.