Sha256: 18a425ad57fc760564858137a82645b664b37586aaeb17bd5e71a1889ed017cc
Contents?: true
Size: 592 Bytes
Versions: 66
Compression:
Stored size: 592 Bytes
Contents
package luhn
func Valid(n string) bool {
d := extract(n)
if len(d) == 0 {
return false
}
last := len(d) - 1
return (check(d[:last])+d[last])%10 == 0
}
func extract(n string) []int {
d := make([]int, 0, len(n))
for _, r := range n {
if r >= '0' && r <= '9' {
d = append(d, int(r-'0'))
}
}
return d
}
func check(d []int) int {
for i := len(d) - 1; i >= 0; i -= 2 {
x := 2 * d[i]
if x > 9 {
x -= 9
}
d[i] = x
}
s := 0
for _, x := range d {
s += x
}
return s
}
func AddCheck(raw string) string {
return raw + string('0'+(10-check(extract(raw))%10)%10)
}
Version data entries
66 entries across 66 versions & 1 rubygems