let b = '11010';
let hex = parseInt(b, 2).toString(16).toUpperCase();
hex = hex.padStart(4, "0")
console.log(hex);
b = '1001101011';
hex = parseInt(b, 2).toString(16).toUpperCase();
hex = hex.padStart(4, "0")
console.log(hex);
/*
run:
"001A"
"026B"
*/