The `bin2hex()` string function in PHP 8.4 converts binary data into its hexadecimal representation. This is particularly useful when you need to encode binary data into a readable format, such as when preparing data for transmission or storage.

Syntax:

<?php
bin2hex(string $string): string
?>

$string: The input string containing binary data.

Return Value:

The function returns a string containing the hexadecimal representation of the input binary data.

Example:

<?php
// Original binary data
$binaryData = "Hello, World!";

// Convert binary data to hexadecimal
$hexadecimal = bin2hex($binaryData);

// Display the hexadecimal representation
echo $hexadecimal; // Outputs: 48656c6c6f2c20576f726c6421

// To convert back from hexadecimal to binary
$originalData = hex2bin($hexadecimal);

// Display the original data
echo $originalData; // Outputs: Hello, World!
?>

In this example, the string “Hello, World!” is converted to its hexadecimal equivalent, resulting in “48656c6c6f2c20576f726c6421”. Using the `hex2bin()` function, we can revert the hexadecimal string back to its original binary form.