How to convert a decimal number to hexadecimal in JavaScript?

Hi everyone! I'm new to JavaScript and ran into a problem while working with numbers. I need to write a function that takes a decimal number (e.g., 255 or 16) and returns its hexadecimal representation as a string. I know that in CSS and HTML, colors are often specified in hex format, like #FF0000, and I want to learn how to get such values programmatically.\n\nI tried using the `toString()` method, but I'm not sure if I'm doing it correctly. Here's my code:\n\n```javascript\nfunction decToHex(num) {\n return num.toString(16);\n}\nconsole.log(decToHex(255)); // Outputs "ff"\n```\n\nThis works, but I want the result to always be in uppercase (e.g., "FF" instead of "ff") and to add a leading zero for numbers less than 16 (e.g., "0A" for the number 10). Additionally, I need to handle