charmatch {base} | R Documentation |
charmatch
seeks matches for the elements of its first argument
among those of its second.
charmatch(x, table, nomatch = NA_integer_)
x |
the values to be matched: converted to a character vector by
|
table |
the values to be matched against: converted to a character vector. Long vectors are not supported. |
nomatch |
the (integer) value to be returned at non-matching positions. |
Exact matches are preferred to partial matches (those where the value to be matched has an exact match to the initial part of the target, but the target is longer).
If there is a single exact match or no exact match and a unique
partial match then the index of the matching value is returned; if
multiple exact or multiple partial matches are found then 0
is
returned and if no match is found then nomatch
is returned.
NA
values are treated as the string constant "NA"
.
An integer vector of the same length as x
, giving the
indices of the elements in table
which matched, or nomatch
.
This function is based on a C function written by Terry Therneau.
startsWith
for another matching of initial parts of strings;
grep
or regexpr
for more general (regexp)
matching of strings.
charmatch("", "") # returns 1
charmatch("m", c("mean", "median", "mode")) # returns 0
charmatch("med", c("mean", "median", "mode")) # returns 2