Strings

Question 1

paste(…)

Answer 1

concatenate vectors after converting to character; sep= is the string to separate terms (a single space is the default); collapse= is an optional string to separate “collapsed” results

Question 2

substr(x,start,stop)

Answer 2

substrings in a character vector; can also as- sign, as substr(x, start, stop) <- value

Question 3

strsplit(x,split)

Answer 3

split x according to the substring split

Question 4

grep(pattern,x)

Answer 4

searches for matches to pattern within x; see ?regex

Question 5

gsub(pattern,replacement,x)

Answer 5

replacement of matches determined
by regular expression matching sub() is the same but only replaces
the first occurrence.

Question 6

tolower(x)

Answer 6

convert to lowercase

Question 7

toupper(x)

Answer 7

convert to uppercase

Question 8

match(x,table)

Answer 8

a vector of the positions of first matches for the elements

of x among table

Question 9

x %in% table

Answer 9

id. but returns a logical vector

Question 10

pmatch(x,table)

Answer 10

partial matches for the elements of x among table

Question 11

nchar(x)

Answer 11

number of characters