**bin2hex() function:**

The `bin2hex()` function in PHP converts a binary string into its hexadecimal representation. It takes a binary string as its argument and returns a string containing the hexadecimal representation of the binary string.

**Syntax:**

“`php
bin2hex(string $binary_string): string
“`

**Parameters:**

* `$binary_string`: The binary string to be converted.

**Return Value:**

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

**Example:**

“`php
$binary_string = “\x48\x65\x6c\x6c\x6f”;
$hex_string = bin2hex($binary_string);

echo $hex_string; // Output: 48656c6c6f
“`

The `bin2hex()` function can be used to convert binary data into a more human-readable format. It is often used for debugging and troubleshooting purposes.

Here are some additional examples of how the `bin2hex()` function can be used:

* Convert a binary file into a hexadecimal string:

“`php
$binary_file = fopen(“binary_file.bin”, “rb”);
$binary_data = fread($binary_file, filesize(“binary_file.bin”));
fclose($binary_file);

$hex_string = bin2hex($binary_data);

echo $hex_string; // Output: 48656c6c6f576f726c64
“`

* Convert a binary string into a hexadecimal string and then back into a binary string:

“`php
$binary_string = “\x48\x65\x6c\x6c\x6f”;
$hex_string = bin2hex($binary_string);

$binary_string_2 = hex2bin($hex_string);

echo $binary_string_2; // Output: Hello
“`

The `bin2hex()` function is a versatile function that can be used to convert binary data into a more human-readable format. It is a core function in PHP and is used in many applications.