Regex for UK Postcode

javascript

const regex = /^[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}$/;
const isValid = regex.test(value);

python

import re
pattern = r'^[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}$'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /^[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}$/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/^[A-Z]{1,2}\d[A-Z\d]? ?\d[A-Z]{2}$/', $value)) {
    echo "valid";
}

java

String pattern = "^[A-Z]{1,2}\\d[A-Z\\d]? ?\\d[A-Z]{2}$";
boolean isValid = value.matches(pattern);