JSFiddle - React, Tailwind, and code Playground
JavaScript
var mystring= 'Hello';
var regex = /^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})$/;
alert(regex.test(mystring));
mystring = '3D:F2:C9:A6:B3:4F';
alert(regex.test(mystring));
var mystring= 'Hello';
var regex = /^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})$/;
alert(regex.test(mystring));
mystring = '3D:F2:C9:A6:B3:4F';
alert(regex.test(mystring));