Reference

Pattern matching
str_count()	Count the number of matches in a string.
str_detect()	Detect the presence or absence of a pattern in a string.
str_extract() str_extract_all()	Extract matching patterns from a string.
str_locate() str_locate_all()	Locate the position of patterns in a string.
str_match() str_match_all()	Extract matched groups from a string.
str_remove() str_remove_all()	Remove matched patterns in a string.
str_replace() str_replace_all()	Replace matched patterns in a string.
str_starts() str_ends()	Detect the presence or absence of a pattern at the beginning or end of a string.
str_split() str_split_fixed()	Split up a string into pieces.
str_subset() str_which()	Keep strings matching a pattern, or find positions.
str_view() str_view_all()	View HTML rendering of regular expression match.
fixed() coll() regex() boundary()	Control matching behaviour with modifier functions.
Whitespace
str_pad()	Pad a string.
str_trim() str_squish()	Trim whitespace from a string
str_wrap()	Wrap strings into nicely formatted paragraphs.
Locale senstive
str_order() str_sort()	Order or sort a character vector.
str_to_upper() str_to_lower() str_to_title() str_to_sentence()	Convert case of a string.
Other helpers
invert_match()	Switch location of matches to location of non-matches.
str_c()	Join multiple strings into a single string.
str_conv()	Specify the encoding of a string.
str_dup()	Duplicate and concatenate strings within a character vector.
str_flatten()	Flatten a string
str_glue() str_glue_data()	Format and interpolate a string with glue
str_length()	The length of a string.
str_replace_na()	Turn NA into "NA"
str_trunc()	Truncate a character string.
str_sub() `str_sub<-`()	Extract and replace substrings from a character vector.
word()	Extract words from a sentence.
Bundled data
sentences fruit words	Sample character vectors for practicing string manipulations.