Converting Decimal to Hexadecimal in JavaScript

In JavaScript, converting decimal numbers to their hexadecimal equivalents is a common task. This process involves representing a decimal number using the base-16 number system, which uses 16 distinct symbols: 0-9 and A-F (or a-f). In this tutorial, we will explore how to perform decimal-to-hexadecimal conversions in JavaScript.

Using the toString(16) Method

The simplest way to convert a decimal number to hexadecimal is by using the toString(16) method. This method takes an integer as input and returns its hexadecimal representation as a string.

let decimalNumber = 255;
let hexString = decimalNumber.toString(16);
console.log(hexString); // Output: "ff"

Note that this method does not handle negative numbers or non-integer values.

Handling Negative Numbers and Non-Integer Values

When dealing with negative numbers or non-integer values, you may need to use additional techniques. One approach is to use bitwise operators to convert the number to a positive hexadecimal representation.

function decimalToHexString(number) {
  if (number < 0) {
    number = 0xFFFFFFFF + number + 1;
  }
  return number.toString(16).toUpperCase();
}
console.log(decimalToHexString(-1)); // Output: "FFFFFFFE"

Alternatively, you can use the zero-fill right shift operator (>>>) to get the two’s-complement hexadecimal representation of a negative number.

let negativeNumber = -2;
let hexString = ((negativeNumber >>> 0).toString(16)).toUpperCase();
console.log(hexString); // Output: "FFFFFFFE"

Adding Padding to Hexadecimal Strings

In some cases, you may want to add padding to the hexadecimal string to ensure it has a minimum length. You can use a while loop to achieve this.

function decimalToHex(d, padding) {
  let hex = Number(d).toString(16);
  padding = typeof padding === "undefined" || padding === null ? 2 : padding;
  while (hex.length < padding) {
    hex = "0" + hex;
  }
  return hex;
}
console.log(decimalToHex(10, 4)); // Output: "000a"

Conclusion

In conclusion, converting decimal numbers to hexadecimal in JavaScript can be achieved using the toString(16) method or by employing additional techniques for handling negative numbers and non-integer values. By understanding these methods, you can write more effective code that handles decimal-to-hexadecimal conversions with ease.