JSFiddle - React, Tailwind, and code Playground

HTML

<button>Validate</button>

JavaScript

$(function() {
  $('button').click(function() { 
      var regex = "(GIR 0AA)|((([A-Z][0-9][0-9]?)|(([A-Z][A-Z][0-9][0-9]?)|(([A-Z][0-9][A-HJKSTUW])|([A-Z][A-Z][0-9][ABEHMNPRVWXY])))) [0-9][A-Z]{2})";
    
    var value = "WR2 6NJ";
    
    var regExObject = new RegExp(regex);
    if(regExObject.exec(value))
    {
      alert('Match');
    }
    else
    {
      alert('No match');
    }
  });
});