Sha256: ee62262cc6815156077ab0bc4667e215656eef26af773d70b59b379956e4efd1
Contents?: true
Size: 946 Bytes
Versions: 114
Compression:
Stored size: 946 Bytes
Contents
package isbn
import (
"errors"
"math"
"strconv"
"unicode"
)
func IsValidISBN(isbn string) bool {
isbn = dropHyphen(isbn)
ary, err := strToSlice(isbn)
if len(ary) != 10 || err != nil {
return false
}
return calcCheckDigit(ary)
}
func dropHyphen(isbn string) string {
var result string
for _, char := range isbn {
if char == '-' {
continue
}
result += string(char)
}
return result
}
func strToSlice(isbn string) (result []int, err error) {
for pos, char := range isbn {
if unicode.IsLetter(char) && (char != 'X' || pos != 9) {
err = errors.New("invalid character")
return
} else if char == 'X' {
result = append(result, 10)
} else {
i, _ := strconv.Atoi(string(char))
result = append(result, i)
}
}
return
}
func calcCheckDigit(isbn []int) bool {
var pool int
for idx, value := range isbn {
pool += int(math.Abs(float64(idx)-10)) * value
}
result := pool % 11
return result == 0
}
Version data entries
114 entries across 114 versions & 1 rubygems