Test if characters are in a string

Question

I'm trying to determine if a string is a subset of another string. For example:

chars <- "test"

value <- "es"

I want to return TRUE if "value" appears as part of the string "chars". In the following scenario, I would want to return false:

chars <- "test"

value <- "et"

Answer 1

You can use grepl() function that returns TRUE if a string contains the pattern, and otherwise returns FALSE.

Basic syntax for grepl() function is given below:

grepl(pattern, x, ignore.case = FALSE, perl = FALSE,

  fixed = FALSE, useBytes = FALSE)

 

In your case:

chars <- "test"

value <- "es"

grepl(value, chars)

[1] TRUE