// http://www.golangprograms.com/regular-expression-to-validate-phone-number.html
// Regular expression to validate phone number
package main
import (
"fmt"
"regexp"
)
func main() {
str1 := "1(234)5678901x1234"
str2 := "(+351) 282 43 50 50"
str3 := "90191919908"
str4 := "555-8909"
str5 := "001 6867684"
str6 := "001 6867684x1"
str7 := "1 (234) 567-8901"
str8 := "1-234-567-8901 ext1234"
re := regexp.MustCompile(`^(?:(?:\(?(?:00|\+)([1-4]\d\d|[1-9]\d?)\)?)?[\-\.\ \\\/]?)?((?:\(?\d{1,}\)?[\-\.\ \\\/]?){0,})(?:[\-\.\ \\\/]?(?:#|ext\.?|extension|x)[\-\.\ \\\/]?(\d+))?$`)
fmt.Printf("Pattern: %v\n", re.String()) // print pattern
fmt.Printf("\nPhone: %v\t:%v\n", str1, re.MatchString(str1))
fmt.Printf("Phone: %v\t:%v\n", str2, re.MatchString(str2))
fmt.Printf("Phone: %v\t\t:%v\n", str3, re.MatchString(str3))
fmt.Printf("Phone: %v\t\t\t:%v\n", str4, re.MatchString(str4))
fmt.Printf("Phone: %v\t\t:%v\n", str5, re.MatchString(str5))
fmt.Printf("Phone: %v\t\t:%v\n", str6, re.MatchString(str6))
fmt.Printf("Phone: %v\t\t:%v\n", str7, re.MatchString(str7))
fmt.Printf("Phone: %v\t:%v\n", str8, re.MatchString(str8))
}