RegEx for matching UK Postcodes

Question

I\'m after a regex that will validate a full complex UK postcode only within an input string. All of the uncommon postcode forms must be covered as well as the usual. For in

Answer 1

Below method will check the post code and provide complete info

const valid_postcode = postcode => {
    try {
        postcode = postcode.replace(/\s/g, "");
        const fromat = postcode
            .toUpperCase()
            .match(/^([A-Z]{1,2}\d{1,2}[A-Z]?)\s*(\d[A-Z]{2})$/);
        const finalValue = `${fromat[1]} ${fromat[2]}`;
        const regex = /^([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([AZa-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9]?[A-Za-z]))))[0-9][A-Za-z]{2})$/i;
        return {
            isValid: regex.test(postcode),
            formatedPostCode: finalValue,
            error: false,
            info: 'It is a valid postcode'
        };
    } catch (error) {
        return { error: true , info: 'Invalid post code has been entered!'};
    }
};

valid_postcode('GU348RR')
result => {isValid: true, formatedPostCode: "GU34 8RR", error: false, info: "It is a valid postcode"}

valid_postcode('sdasd4746asd')
result => {error: true, info: "Invalid post code has been entered!"}

valid_postcode('787898523')
result => {error: true, info: "Invalid post code has been entered!"}