Validate Canadian Postal Code Regex

Question

I have written a JavaScript to validate Canadian Postal Codes using regex.

However, it does not seem to be working:

JavaScript

If statement:

if (myform.zip.value == "" || myform.zip.value == null || myform.zip.value == "Postal Code" || myform.zip.value.length < 12 ) {
    alert("Please fill in field Postal Code. You should only enter 7 characters");
    myform.zip.focus();
    return false;
}

Function:

function okNumber(myform) {
  var regex = /^[ABCEGHJKLMNPRSTVXY]{1}\d{1}[A-Z]{1} *\d{1}[A-Z]{1}\d{1}$/;
  if (regex.test(myform.zip.value) == false) {
    alert("Input Valid Postal Code");
    myform.zip.focus();
    return false;
  }

  return true;
}

Problem

It doesn't work at all, although code is executing. When I run it, I get:

Please fill in field Postal Code. You should only enter 7 characters

An example valid postal code would be T2X 1V4.

Answer 1

A regex approach can validate the format of a Canadian postcode, but it's not sufficient to guarantee that the postcode actually exists.

For example: A9A 0A0 looks like a valid Canadian postcode, but the forward sortation area A9A doesn't actually exist.

Are you sure you wouldn't rather do some kind of lookup against an official list of postcodes?