US ZIP Code in GO

Match US ZIP codes in 5-digit (12345) and ZIP+4 (12345-6789) formats.

Pattern

\b\d{5}(?:[\-\s]\d{4})?\b   (flags: g)

Go (RE2) code

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`\b\d{5}(?:[\-\s]\d{4})?\b`)
	input := `90210`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

How the pattern works

Examples

Same pattern, other engines