I have an array of characters like this :
chars := []string{".", "-", "(", ")"}
When I join them in regular way (strings.Join(chars, "")) and pass it to regexp.MustCompile, Its panic :
panic: regexp: Compile(`[.-()]`): error parsing regexp: invalid character class range: `.-(`
How can I scape string special characters for use in golang regexp as a character not regexp operator?
You must put the - item at the start/end of the array so that - appears either at the start - [-.()] - or end - [.()-] - of the character class.
Or escape the - in the chars array: "\\-".
NOTE: That is not the only caveat, the ^ and ] must also be escaped, or placed in a specific location in the character class. The \ must be escaped always.
See a Go demo:
package main
import (
"fmt"
"strings"
"regexp"
)
func main() {
chars := []string{"]", "^", "\\\\", "[", ".", "(", ")", "-"}
r := strings.Join(chars, "")
s := "[Some]-\\(string)^."
re := regexp.MustCompile("[" + r + "]+")
s = re.ReplaceAllString(s, "")
fmt.Println(s)
}
Output: Somestring
Note that the ^ must not be the first item, ] must be at the start and - at the end.
Now there is an even better way:
regexp.MustCompile( regexp.QuoteMeta(strings.Join(chars, "")) )
regexp.QuoteMeta() will create a regular expression that matches the string provided exactly (i.e. it will escape all the regex meta-characters).
