Efficient regex for Canadian postal code function

Question

var regex = /[A-Za-z]\\d[A-Za-z] ?\\d[A-Za-z]\\d/;
var match = regex.exec(value);
if (match){
    if ( (value.indexOf(\"-\") !== -1 || value.indexOf(\" \") !== -1 )          


        

Answer 1

This one handles us and ca codes.

function postalFilter (postalCode) {

    if (! postalCode) {
        return null;
    }

    postalCode = postalCode.toString().trim();

    var us = new RegExp("^\\d{5}(-{0,1}\\d{4})?$");
    var ca = new RegExp(/([ABCEGHJKLMNPRSTVXY]\d)([ABCEGHJKLMNPRSTVWXYZ]\d){2}/i);

    if (us.test(postalCode.toString())) {
        return postalCode;
    }

    if (ca.test(postalCode.toString().replace(/\W+/g, ''))) {
        return postalCode;
    }
    return null;
}

// these 5 return null
console.log(postalFilter('1a1 a1a'));
console.log(postalFilter('F1A AiA'));
console.log(postalFilter('A12345-6789'));
console.log(postalFilter('W1a1a1')); // no "w"
console.log(postalFilter('Z1a1a1')); // ... or "z" allowed in first position!

// these return canada postal less space
console.log(postalFilter('a1a 1a1'));
console.log(postalFilter('H0H 0H0'));

// these return unaltered
console.log(postalFilter('H0H0H0'));
console.log(postalFilter('a1a1a1'));
console.log(postalFilter('12345'));
console.log(postalFilter('12345-6789'));
console.log(postalFilter('123456789'));

// strip spaces
console.log(postalFilter(' 12345 '));