Assessment and Cataloging

get_isbn_10_check_digit

R Documentation

Get ISBN 10 check digit

Description

Takes a string representation of an ISBN 10 and returns the check digit that satisfies the necessary condition. It can take a 10 digit string (and ignore the already extant check digit) or a 9 digit string (without the last digit)

Usage

get_isbn_10_check_digit(x, allow.hyphens = FALSE, errors.as.nas = FALSE)

Arguments

`x`	A string of 9 or 10 digits
`allow.hyphens`	A logical indicating whether the hyphen separator should be allowed (default is `FALSE`)
`errors.as.nas`	return NA if error instead of throwing error (default is `FALSE`)

Value

Returns the character check digit that satifies the mod 11 condition. Returns "X" if 10. Returns NA if input is NA

Examples


get_isbn_10_check_digit("012491540X")
get_isbn_10_check_digit("0-124-91540-X", allow.hyphens=TRUE)

# nine digit string
get_isbn_10_check_digit("900403781")

get_isbn_10_check_digit("onetwothre", errors.as.nas=TRUE)  # NA

# vectorized
get_isbn_10_check_digit(c("012491540X", "9004037810", "900403781"))

NYPL/libbib documentation built on Feb. 6, 2024, 4:19 a.m.