Count the Number of Pattern Occurrences

These functions count the number of occurrences of a pattern in a string.

Usage

stri_count(str, ..., regex, fixed, coll, charclass)

stri_count_charclass(str, pattern)

stri_count_coll(str, pattern, ..., opts_collator = NULL)

stri_count_fixed(str, pattern, ..., opts_fixed = NULL)

stri_count_regex(str, pattern, ..., opts_regex = NULL)

Arguments

str

character vector; strings to search in

...

supplementary arguments passed to the underlying functions, including additional settings for opts_collator, opts_regex, opts_fixed, and so on

pattern, regex, fixed, coll, charclass

character vector; search patterns; for more details refer to stringi-search

opts_collator, opts_fixed, opts_regex

a named list used to tune up the search engine's settings; see stri_opts_collator, stri_opts_fixed, and stri_opts_regex, respectively; NULL for the defaults

Value

All the functions return an integer vector.

Details

Vectorized over str and pattern (with recycling of the elements in the shorter vector if necessary). This allows to, for instance, search for one pattern in each given string, search for each pattern in one given string, and search for the i-th pattern within the i-th string.

If pattern is empty, then the result is NA and a warning is generated.

stri_count is a convenience function. It calls either stri_count_regex, stri_count_fixed, stri_count_coll, or stri_count_charclass, depending on the argument used.

See also

The official online manual of stringi at https://stringi.gagolewski.com/

Gagolewski M., stringi: Fast and portable character string processing in R, Journal of Statistical Software 103(2), 2022, 1-59, doi:10.18637/jss.v103.i02

Other search_count: about_search, stri_count_boundaries()

Author

Marek Gagolewski and other contributors

Examples

s <- 'Lorem ipsum dolor sit amet, consectetur adipisicing elit.'
stri_count(s, fixed='dolor')
#> [1] 1
stri_count(s, regex='\\p{L}+')
#> [1] 8

stri_count_fixed(s, ' ')
#> [1] 7
stri_count_fixed(s, 'o')
#> [1] 4
stri_count_fixed(s, 'it')
#> [1] 2
stri_count_fixed(s, letters)
#>  [1] 2 0 3 2 5 0 1 0 7 0 0 2 3 2 4 2 0 3 4 5 2 0 0 0 0 0
stri_count_fixed('babab', 'b')
#> [1] 3
stri_count_fixed(c('stringi', '123'), 'string')
#> [1] 1 0

stri_count_charclass(c('stRRRingi', 'STrrrINGI', '123'),
   c('\\p{Ll}', '\\p{Lu}', '\\p{Zs}'))
#> [1] 6 6 0
stri_count_charclass(' \t\n', '\\p{WHITE_SPACE}') # white space - binary property
#> [1] 3
stri_count_charclass(' \t\n', '\\p{Z}') # white-space - general category (note the difference)
#> [1] 1

stri_count_regex(s, '(s|el)it')
#> [1] 2
stri_count_regex(s, 'i.i')
#> [1] 2
stri_count_regex(s, '.it')
#> [1] 2
stri_count_regex('bab baab baaab', c('b.*?b', 'b.b'))
#> [1] 3 2
stri_count_regex(c('stringi', '123'), '^(s|1)')
#> [1] 1 1