javascript
const regex = /^[a-z0-9]+(?:-[a-z0-9]+)*$/;
const isValid = regex.test(str);
python
import re
pattern = re.compile(r'^[a-z0-9]+(?:-[a-z0-9]+)*$')
is_valid = bool(pattern.match(text))
go
import "regexp"
re := regexp.MustCompile(`^[a-z0-9]+(?:-[a-z0-9]+)*$`)
isValid := re.MatchString(text)