match
Match Items against a Table

### Description

Returns a vector of the positions in table of the elements of x.

### Usage

    match(x, table, nomatch = NA_integer_, incomparables = NULL)

### Arguments

x | a vector of items to find in table. Missing values and Infs are allowed. Factors are treated as characters.
table | the possible values in x. Missing values and Infs are allowed.
nomatch | the value to return when an item in x matches no item in table. A useful alternative to NA is nomatch=0, which ignores unmatched items when the matched indices are used in subscripts (see the last example below). The value is coerced to an integer.
incomparables | a vector of values that the function cannot match. Any value in x that matches a value in this vector is assigned the value specified by nomatch. If incomparables is NULL or FALSE, all values can be matched.

### Details

Comparisons are done in the simplest mode that does not imply information loss. For example, if both x and table are numeric, then comparisons are numeric. If either x or table is a character string, then comparisons are of character strings. NaN is considered distinct from NA.
Value
returns an integer vector of the same length as x giving, for each element of x, the smallest i such that table[i] equals that element, or nomatch if there is no match.
See Also
regMatch, charmatch, pmatch, is.element, union, intersect, setdiff, matchlist.
Examples

    x <- 1:10
    primes <- c(2, 3, 5, 7, 11, 13, 17, 19, 23)
    match(x, primes)
    match(x, primes, incomp=2)       # match to all primes but 2
    names <- c('Washington', 'New York', 'Sweden', 'Florida')
    # change names to abbrevs (NA for 'Sweden')
    Sdatasets::state.abb[match(names, Sdatasets::state.name)]
    # filter out non-state names ('Sweden')
    names[match(Sdatasets::state.name, names, 0)]

Package base version 6.1.5-18
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