1:  const hex = 0xff;       // Number from hexadecimal. This is number type in Javascript. There is no separate hex type.

   2:  const numFromHex = hex;

   3:  const strHex = hex.toString(16);  // Convert number to hex string.

   4:  console.log(strHex); // ff

   5:  const numFromStrHex = parseInt(strHex, 16); // Parse int from hex string

   6:  console.log(numFromStrHex);