Validationflags: gi

Canadian Postal Code

Match Canadian postal codes in the A1A 1A1 or A1A1A1 format with valid first-letter prefixes.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("[ABCEGHJ-NPRSTVXY]\\d[A-Z] ?\\d[A-Z]\\d", "gi");
const input = "K1A 0B1";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"[ABCEGHJ-NPRSTVXY]\d[A-Z] ?\d[A-Z]\d", re.IGNORECASE)
input_text = "K1A 0B1"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(?i)[ABCEGHJ-NPRSTVXY]\d[A-Z] ?\d[A-Z]\d`)
	input := `K1A 0B1`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

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

Pattern

regexengine-agnostic

[ABCEGHJ-NPRSTVXY]\d[A-Z] ?\d[A-Z]\d   (flags: gi)

Raw source: [ABCEGHJ-NPRSTVXY]\d[A-Z] ?\d[A-Z]\d

How it works

The leading character is constrained to letters actually used by Canada Post (D, F, I, O, Q, U, W, Z are excluded). Alternating letter-digit pattern, with an optional space separator.