PHP hex2bin() Function

The hex2bin() function is a built-in function in PHP. The hex2bin() function is used to decode a hexadecimally encoded binary string. That is, it decodes a binary string which is encoded in hexadecimal representation back to binary representation.

Note: The purpose of this function is not to convert a hexadecimal number to binary number, to do so we can use the base_convert() function in PHP. This function is just used to decode a hexadecimally encoded binary string.

Syntax:

string hex2bin($hexString)

Parameters: This function accepts a single parameter $hexString which represents a hexadecimal data which is needed to be decoded to binary representation.

Return Value: This function return a string which is the binary representation of the hexa-decimal input $hexString. If this function fails to decode the hexadecimal string to binary then it returns False.

Examples:

Input : $hexString = "48656c6c6f20576f726c6421"
Output : Hello World!

Input : $hexString = "6578616d706c65206865782064617461" 
Output : example hex data

Below programs illustrate the hex2bin() function:

Program 1:

<?php

echo hex2bin("48656c6c6f20576f726c6421");

?>

Output:

Hello World!

Program 2:

<?php

echo hex2bin("6578616d706c65206865782064617461");

?>

Output:

example hex data

Reference:
http://php.net/manual/en/function.hex2bin.php